dhcp static assignment motorola

How do I setup a Static IP address on my device?

To setup a Static IP Address on your device, follow the steps below:

• Touch  Apps
• Touch Settings
• Touch Wi-Fi settings
• Touch Add Wi-Fi network
• Enter Name under Network SSID , and touch Save
• Touch and hold the "network name" , and touch Modify network
• Select Static under IP settings, and enter the specific network information Tip : You can also adjust your security and Proxy settings.

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How do I setup and troubleshoot Wi-Fi issues?

Follow these steps to set up and troubleshoot Wi-Fi wireless Internet access.

Turn Wi-Fi power on or off

Wi-Fi search & connect

To search for a network when Wi-Fi is off :

Touch the Wi-Fi power switch to turn it On and scan. Your smartphone lists the networks it finds within range.

Touch a network to connect. If necessary, enter Network SSID , Security , and Password , and touch Connect

Tip : When you are in range and Wi-Fi power is on, you will automatically reconnect to available networks you’ve connected to before.

Wi-Fi Hotspot

You can make your smartphone a Wi-Fi hotspot to provide portable, convenient Internet access to other Wi-Fi enabled devices.

Caution : This application significantly impacts battery life. You may want to run this application with the charger connected.

Note : You need to subscribe to Wi-Fi hotspot service to use this feature. Contact your carrier for more details.

To set up your smartphone as a Wi-Fi hotspot:

Touch Mobile Hotspot settings > Configure Mobile Hotspot to change hotspot security and configuration settings:

Network SSID : Enter a unique name for your hotspot and touch Next .

Security : Select the type of security you want: WEP , WPA , or WPA2 . Enter a unique password. Other users can access your Wi-Fi hotspot only if they enter the correct password.

Note : Keep it secure. To protect your smartphone and hotspot from unauthorized access, it is strongly recommended that you set up hotspot Security ( WPA2 is the most secure), including password.

Broadcast Channel : Select a channel that minimizes potential interference. You may need to try different channels after your hotspot is active for a time.

Touch Save when the settings are complete.

When your Wi-Fi hotspot is active, other Wi-Fi enabled devices can connect by entering your hotspot’s SSID , selecting a Security type, and entering the correct Password .

Troubleshooting

Unable to establish connection with the phone

• The wireless network may not be in range or has too of a weak signal to provide a successful connection. Check the signal bar to ensure you have strong connection.
• Re-enter the key on the phone to match the key configured on the router. Make sure that the encryption type and security settings match on the router and phone.
• If WEP encryption is in use, check that the key configured on the router matches the key entered on the phone.
• The wireless network you're attempting to connect to may be configured for static IP addresses only. Check with the system administrator for an IP address assignment.
• Unplug the power from your router, turn the phone off. Plug back in your router first, then wait for 1 minute and then turn on your phone.
• Check if you are able to connect your phone via Bluetooth. If also unable to connect via Bluetooth contact Motorola for repair options.

Can't connect to Internet

• Try a different URL or web site address.
• Disconnect and try connecting to the network again.
• Enter correct Password (WEP-WAP/WPA key).
• If connected via a commercial Wi-Fi hotspot, such as the ones at Borders or Starbucks, we recommend renewing the hotspot's DHCP lease.

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Setting a static IP address on the network...

• Please log in to reply

• Local time: 03:59 AM

Posted 20 September 2014 - 09:32 AM

I'm using a Motorola Surfboard SBG6580 as my modem/router. I have a wireless network generated from a TEW-637AP that is repeated on the other side of my house by an Amped Wireless SR300. The SR300 has its own SSID and IP. I have a printer and a laptop that regularly connect to the SR300's network and I would like to be able to set static IP addresses for them both and I was wondering what is the simplest way to go about doing this? The laptop is an Acer and the printer is a Brother HL-2270DW.

Based on what I've read there are a few different ways to do this and I want to choose the one that is the least beset by complication. Many thanks.

Edited by hamluis, 20 September 2014 - 10:29 AM. Moved from Win 7 to Networking - Hamluis.

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#2 SleepyDude

• Malware Response Team
• 4,173 posts
• Gender: Male
• Location: Portugal
• Local time: 09:59 AM

Posted 20 September 2014 - 10:37 AM

The simple way is to find what device is acting as DHCP server in your network and check if the DHCP configuration allow you to associate a fixed IP to the device, this way you don't need to do any changes on the clients when you need to connect to other wireless networks.

#3 CaveDweller2

• 2,629 posts
• Local time: 04:59 AM

Posted 21 September 2014 - 08:06 AM

As long as the address is on the same network you can just give it an address. Go into the properties of the wireless connection you are using, the IPv4 properties, click on Use the Following address and enter the information. 

If your DHCP hands out 192.168.1.x just make the X a number that is not being used. Most routers out of the box start DHCP assignments at a number other than the lowest they can I think Linksys starts at 192.168.1.100 and hand out addresses above that but the range is from 192.168.1.1 -  254 provided you don't mess with the subnet mask. so any address not in use that is in that range will work.

The printer should have a static IP just in case something happens and it gets assigned a different IP then you have set in the PCs so you don't have to go fix each PC. The computer is either way is fine.

#4 Wand3r3r

• 2,027 posts
• Local time: 01:59 AM

Posted 23 September 2014 - 10:38 AM

What SleepyDude is referring to is called ip reservations.  This is where you associated the mac address of the device with the dhcp address you want it to have.  You can do this IF your routers dhcp server supports it.

Otherwise you have to do make sure you statically assign ips that are not in the dhcp scope or you will cause a ip conflict.

• Topic Starter

Posted 28 September 2014 - 07:22 PM

I heard back from Brother tech and set the static IP through one of their utilities.

Thanks for your help.

• 4,283 posts
• Location: Launderdale, MN

Posted 28 September 2014 - 09:37 PM

The issues you normally see when you set the static IP on the device, instead of through the DHCP server, is the IP changes after a power loss or a duplicate IP address.  The duplicate IP address is more likely if the static IP address you set is within the DHCP range.

#7 SleepyDude

Posted 29 September 2014 - 03:29 AM

I heard back from Brother tech and set the static IP through one of their utilities.   Thanks for your help.

Don't forget to remove the static IP if you want to connect to a different wireless network.

• Location: Behind a keyboard

Posted 29 September 2014 - 11:40 AM

Or just use a static outside the range. Hence why I never make a range from 2 to 254. 

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MG8702 Cable Modem/gateway - Configuring a static IP address manually

Hello. I bought an MG8702 running version 8702-19.3.9.

I have a static IP address through my ISP, but it needs to be configured manually at the router and cannot be allocated through the DHCP infrastructure.

I've gone through the advanced configuration screens and cannot find where to set that up. Does it exist? Is it hidden? Do I need to return this box and get (to stick with Motorola) an MB8611 cable modem and an MR2600 wifi router?

I've opened a ticket with Motorola support, 320981, but haven't heard anything back from them. I've tried phone support as well, but it hangs up after about 30 minutes and the one time I did get through, the call disconnected right when we got through the serial number.

Thanks for your help!

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[SOLVED]   How do I assign a static IP through DHCP?

• Thread starter redteamrocks
• Start date Feb 26, 2019
• Tags DHCP internet protocol networking issue

redteamrocks

• Feb 26, 2019

Hello friends, I have a server that I plan to use as a file server in my house that I want to have a static IP so we can always access it from our computers. How do I configure this so that all of my other computers can continue to use DHCP from the ISP to get their info? Thanks, Matt  

• Feb 27, 2019

redteamrocks said: Hello friends, I have a server that I plan to use as a file server in my house that I want to have a static IP so we can always access it from our computers. How do I configure this so that all of my other computers can continue to use DHCP from the ISP to get their info? Thanks, Matt Click to expand...

There are 2 basic ways. You can assign the ip directly in the server being sure that the ip is in a range excluded on the router so it does not assign it to another machine. The other way is to use a feature in the router...most have it...to assign the static ip via dhcp. You would put in the ip you want to use and the mac address of the server. The router would then always offer the same IP via dhcp anytime it gets a request from that mac address.  

SkyNetRising

If all your computers get IP address from ISP, then only ISP can make address reservation. If you have router between your network and ISP (your router gives IP addresses to your local network), then you can make IP address reservation in router. This will reserve local IP address of your server. External IP address will still be controlled by ISP. ISP may charge extra for external address reservation.  

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Ashish_maurya.

• Mar 2, 2019

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How do I setup a Static IP address on my device?

To setup a Static IP Address on your device, follow the steps below:

• Touch  Apps
• Touch Settings
• Touch Wi-Fi settings
• Touch Add Wi-Fi network
• Enter Name under Network SSID , and touch Save
• Touch and hold the "network name" , and touch Modify network
• Select Static under IP settings, and enter the specific network information Tip : You can also adjust your security and Proxy settings.

Was this answer helpful?

Let's stay in touch:

Stack Exchange Network

Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

Assigning a fixed IP address to a machine in a DHCP network

I want to assign a fixed private IP address to a server so that local computers can always access it.

Currently, the DHCP address of the server is something like 192.168.1.66 .

Should I simply assign the server this same IP as fixed and configure the router so that it will exclude this IP from the ones available for DHCP? Or are there some ranges of IP that are traditionally reserved for static addresses?

My beginner's question doesn't relate to commands but to general principles and good practices.

Practical case (Edit 1 of 2)

Thank you for the many good answers, especially the very detailed one from Liam.

I could access the router's configuration.

When booting any computer, it obtains its IPv4 address in DHCP.

The IP and the MAC addresses that I can see with the ipconfig all command in Windows match those in the list of connected devices that the router displays, so that I can confirm who is who.

The list of connected devices is something like

Things that I don't understand:

• Although all IP addresses are all obtained in DCHP, they are displayed as by the router as if they are static addresses.
• The router's setting "Enable DHCP on LAN" is set on "Off" but the IP addresses are obtained in DHCP.
• IP addresses attributed to the computers are outside of the very narrow DHCP range of 192.168.1.33 to 192.68.1.35

On any Windows computer connected in DCHP, ipconfig /all shows something like:

I'm missing something, but what?

Practical case (Edit 2 of 2)

Solution found.

For details, see my answer to Michal's comment at the bottom of this message.

I must admit that the way the router display things keeps some parts a mystery. The router seems to be using DHCP by default, but remembers the devices that were connected to it (probably using their mac address). It could be the reason why it lists the IPs as static although they're dynamic. There was also Cisco router at 192.168.1.4 which appeared for some business communications service, but I had no credentials to access it.

• There's no standard governing DHCP reservation ranges, but it would be kinda nice. –  LawrenceC Commented Apr 5, 2018 at 2:43
• Some routers allow you to define an IP for a chosen mac-address. Use that and DHCP will keep that address for your server. You could also set a DHCP range to e.g. 192.168.0.128 - 192.168.0.254 in a 192.168.0.1/255.255.255.0 network and set all static addresses on the "static" servers from within 192.168.0.2 - 192.168.0.127 range. –  Michal B. Commented Apr 5, 2018 at 7:29
• @Michal B.: I agree and did it meanwhile.: 1. Obtain the server's mac address. 2. Observe which IPs the router assigns to computers (eg. 192.168.0.50 to 192.168.1.70 ) 3. Start the server in DHCP. In the router panel, name it, basing on its mac address so that the router will remember it. 4. In the server switch IP from DHCP mode to manual and assign an IP that is beyond the ones that the router would assign to other devices (eg. 192.168.1.100 ). You can use nmtui and then edit the config file where you can replace PREFIX=32 by NETMASK=255.255.255.0 . 6. Restart the network service. –  OuzoPower Commented Apr 6, 2018 at 9:58

7 Answers 7

Determine the IP address that is assigned to your server and then go onto the DHCP and set a DHCP reservation for that server.

• 1 Reservations are essentially self-documenting. ++ –  mfinni Commented Apr 4, 2018 at 21:30
• 5 @mfinni ++ only works for programmers. -- for your comment :P –  Canadian Luke Commented Apr 4, 2018 at 23:59
• ..and yes he should also use a fixed IP, and label it. Document it. Maybe even reserve a range for this. In an enterprise using internal VPN it is common for these IP's to be hard coded in HOSTS files and SSH config files so it is a big deal when they suddenly change. –  mckenzm Commented Apr 5, 2018 at 1:30

DHCP services differ across many possible implementations, and there are no ranges of IP that are traditionally reserved for static addresses; it depends what is configured in your environment. I'll assume we're looking at a typical home / SOHO setup since you mention your router is providing the DHCP service.

Should I simply assign the server this same IP as fixed and configure the router so that it will exclude this IP from the ones available for DHCP?

I would say that is not best practice. Many consumer routers will not have the ability to exclude a single address from within the DHCP range of addresses for lease (known as a 'pool'). In addition, because DHCP is not aware that you have "fixed" the IP address at the server you run the risk of a conflict. You would normally either:

• set a reservation in DHCP configuration so that the server device is always allocated the same address by the DHCP service, or
• set the server device with a static address that is outside the pool of addresses allocated by the DHCP service.

To expand on these options:

Reservation in DHCP

If your router allows reservations, then the first, DHCP reservation option effectively achieves what you have planned. Note the significant difference: address assignment is still managed by the DHCP service, not "fixed" on the server. The server still requests a DHCP address, it just gets the same one every time.

Static IP address

If you prefer to set a static address, you should check your router's (default) configuration to determine the block of addresses used for DHCP leases. You will normally be able to see the configuration as a first address and last address, or first address and a maximum number of clients. Once you know this, you can pick a static address for your server.

An example would be: the router is set to allow a maximum of 128 DHCP clients with a first DHCP IP address of 192.168.1.32. Therefore a device could be assigned any address from 192.168.1.32 up to and including 192.168.1.159. Your router will use a static address outside this range (generally the first or last address .1 or .254) and you can now pick any other available address for your server.

It depends on the configuration of your DHCP service. Check the settings available to you for DHCP then either reserve an address in DHCP or pick a static address that is not used by DHCP - don't cross the streams.

• 1 Double++ on this. –  ivanivan Commented Apr 5, 2018 at 3:26
• 1 Thank you Liam for your very detailed and useful answer. After accessing the router's configuration, other issues arised that I added in the original message. –  OuzoPower Commented Apr 5, 2018 at 9:45
• @OuzoPower I'm new to responding here so don't have enough rep to comment on the question. Your update shows your router is not providing the DHCP service. The setting is off on the router, and your Windows ipconfig output shows the DHCP service is provided from a device at 192.168.1.5 . Do you have Pi-Hole or another similar device providing DHCP? That's where you'll find your DHCP configuration. NB: This also explains why the router shows the addresses as static and why DHCP assigned addresses are outside the range configured on the router. –  Liam Commented Apr 6, 2018 at 9:52
• @Liam: No Pi-Hole or similar thing as far as I know. Solution found: As I could not set DHCP ranges in the router but could register the mac address of the server in the router and then attribute to the server a fixed IP address that is far beyond the range that the router is naturally assigning to existing devices. Thanks to the registration of the server's mac address, the router keeps it in memory and shows the server as missing when thus is off. For details, see my answer to Michal B. in the original post. This solution seems working like a charm. –  OuzoPower Commented Apr 6, 2018 at 10:11
• @OuzoPower That approach may work in the short term but how do you know that the address you have picked is outside the DHCP range? Many DHCP systems pick addresses at random from the available pool. At some point you will need to know what your DHCP configuration actually is, rather than estimating by observation (!) otherwise you will experience some conflict. Your question asked about best practice. Here, best practice would be to know what system is handling DHCP for your LAN. I would start by visiting 192.168.1.5 or https://192.168.1.5/ for clues. –  Liam Commented Apr 6, 2018 at 10:48

It's not a bad habit to divide your subnet to DHCP pool range and static ranges, but of course you can do what JohnA wrote - use reservation for your server, but first case is IMHO clearer, because you are not messing up your DHCP server with unused extra settings (it could be confusing then for another admins who are not aware of that the server is static). if using DHCP pool + static pool, then just don't forget to add your static server to DNS (create A/AAAA record for it).

• I would like to add that the downside of DHCP reservations for servers is that if your DHCP environment is not sufficient fault tolerant, a DHCP server outage could cause all manner of problems. Monitor the DHCP closely and set leases that are long enough to be able respond to problems even after a long weekend. –  JohnA Commented Apr 5, 2018 at 2:06

I prefer to set my network devices, servers, printers, etc. that require a static IP address out of range of the DHCP pool. For example, xx.xx.xx.0 to xx.xx.xx.99 would be set aside for fixed IP assignments and xx.xx.xx.100 to xx.xx.xx.250 would be set as the DHCP pool.

• I like this approach as well. This way I can still access the servers even if the DHCP server takes the morning off or decides to start handing out invalid leases! –  ErikF Commented Apr 5, 2018 at 1:24
• Using isc-dhcp-server this is required (this is what my pi does, along with DNS caching, a fake domain for my LAN, and some traffic shaping for some wireless stuff). Unfortunately, I've seen browser based router config pages (both factory and replacement) that either require a reserved address to be in the dynamic pool... or out of it. –  ivanivan Commented Apr 5, 2018 at 3:30

In addition to the other answers I want to concentrate on the fact that your router configuration does not seem to fit the IP address configuration on your server.

Please have a look on the output of ipconfig /all:

IPv4 Address ........ 192.168.1.xx(prefered)

Default Gateway ........ 192.168.1.1 (= IP of the router)

DHCP server ............ 192.168.1.5

The clients in the network don't get the IP address from the router, but a different DHCP server in the network (192.168.1.5 instead of 192.168.1.1). You have to find this server and check it's configuration instead of the router's DHCP server config, which is seemingly only used for Wireless.

My router ( OpenWRT ) allows for static DHCP leases.

Static leases are used to assign fixed IP addresses and symbolic hostnames to DHCP clients.

So, you supply the MAC address of the server and it's desired IP address as a "static lease", and DHCP will always allocate the same IP. The client machine (the server in this case) requires no configuration changes and still picks up its IP address (the configured address) from DHCP.

Note that you can't assign a fixed IP addresses in 192.168 so that clients can "always access it" unless you also give each client a fixed IP address and subnet. Because if the clients use DHCP, then they get whatever subnect the DHCP server gives them, and if they use automatic addressing, then they won't be in a 192.168 subnet.

Once you realise that the system can't be easily perfected, you can see that your best options depend on what you are trying to do. Upnp is a common way of making devices visible. DNS is a common way of making devices visible. WINS is a common way of making devices visible. DHCP is a common way of making devices visible.

All of my printers have reservations: my printers aren't critical infrastructure, I want to be able to manage them, many of the clients use UPNP or mDNS for discovery anyway.

My gateway and DNS servers have fixed IP address in a reserved range: My DHCP server provides gateway and DNS addresses, and my DHCP server does not have the capacity to do dynamic discovery or DNS lookup.

None of my streaming devices have fixed or reserved IP values at all: if the network is so broken that DHCP and DNS aren't working, there is no way that the clients will be able to connect to fixed IP addresses anyway.

• This literally makes no sense. Are you asserting that you can’t mix static and dynamic in a /16? –  Gaius Commented Apr 5, 2018 at 12:59
• I have asserted that if you use static, you haven't gauaranteed that clients can "always access it"Not at all. I've just asserted that I've mixed static and dynamic in my setup. –  user165568 Commented Apr 6, 2018 at 9:46
• @Gaius I have asserted that if you use static, you haven't guaranteed that clients can "always access it". I'm sorry that doesn't make sense to you: it's one of the primary reasons the world moved away from static. I've also asserted that I've mixed static and dynamic in my setup: see: "none of my streaming devices have fixed or reserved" and "DNS servers have fixed IP": the DNS servers are indeed in the same subnet as the clients. –  user165568 Commented Apr 6, 2018 at 9:52
• Sorry, but I must admin not understanding most of your answer. As far as I know, DNS are domain name servers and are useful when you want to name servers, like when assigning domain names to web sites. As I don't need domain names, DNS appears me useless. Accessing the server is not an issue without DNS. See my answer to Michal B. in the original post for the solution that I found. –  OuzoPower Commented Apr 6, 2018 at 10:18

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Notify router (DHCP) of static ip assignment

I have been working with the GUI Network Manager (Method 1 in the link below) for over a year on Ubuntu 20.04 to set static ip addresses for all Ubuntu devices.

While this solution has been working well so far, I have been wondering if there is a chance that:

• One Ubuntu device is removed from the network and the DHCP allocates that IP address to another device will there be a clash if the original Ubuntu device comes online?
• DHCP allocates the same IP address to another new device resulting in an IP clash with an already existing static Ubuntu device configured using the GUI network manager

Alternatively, /etc/netplan/ configurations seem to be better because they go through the DHCP to request for a static ip if possible (this is Method 2 in the link below).

TLDR: Is method 2 (The “Ubuntu Server” steps.) in the link below better than method 1 (The “Ubuntu Desktop” steps.) in the link?

Link: https://linuxconfig.org/how-to-configure-static-ip-address-on-ubuntu-18-10-cosmic-cuttlefish-linux

==== Edit, the answer I have come to accept, thanks Tom Yan ==== If the router is inaccessible, use Method 2 to request for a particular IP address first, if unable then a dynamic IP address will be set but at least this avoids IP conflicts with other devices if Method 1 was used. The best method would be to of course reserve an IP address (192.168.1.12) using the MAC address of the device by adjusting the DHCP settings on the router. One step further would to assign dynamic IP addresses outside of this range (192.168.1.50 to 192.168.1.150)

• Normally if you do both DHCP and static with one IP subnet in a broadcast domain, you'll split the subnet into two ranges (not subnet though) of IPs and use each of them for each type of assignment. Even most of the cheapest / consumer-grade routers allow you to set the range for DHCP. –  Tom Yan Commented Jan 6, 2022 at 4:16
• 1 And slightly better routers should allow you to configure "DHCP reservation", with the most sensical approach being using the MAC addresses of the hosts as mappings for IPs that should be assigned to each of the hosts that relies on DHCP for IP configuration. –  Tom Yan Commented Jan 6, 2022 at 4:19
• they go through the DHCP to request for a static ip if possible this makes so sense at all and neither does the article mention any nonsense like that. –  Tom Yan Commented Jan 6, 2022 at 4:23
• There's not exactly any way to prevent you or anyone from configuring any of the "reserved" IPs statically on a host. Whether you can prevent them from "interfering" the mapped hosts depends on the router. Usually no for cosumer-grade, AFAIK, coz that's more of a human error than a security issue in the home-use cases. –  Tom Yan Commented Jan 6, 2022 at 4:28
• Right, so from what I understand from your comments, if I were to set a static IP Address using either the GUI Network Manager or the /etc/netplan/ configuration it is setting the static IP on the host alone but it does not rule out the possibility of the router assigning that IP address to a new device unless a DHCP reservation is explicitly stated? According to superuser.com/questions/487607/… the best approach seems to be to request to see if an IP is available first before assigning it statically –  javdevcpy Commented Jan 6, 2022 at 4:39

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XB6 - how to set static DHCP reservation for LAN devices ?

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Static ip vs dhcp reservation.

In the many years I’ve been providing IT Services , I’ve noticed that whenever taking over a customer from a competitor, or providing consulting services for a company that has IT staff, that I don’t see DHCP reservations being used all that frequently.

I wanted to write a post and create a video to discuss the comparison, when each should be used and the various case scenarios. I’m hoping my readers may provide their own input in the comments.

See below for the video, or read on for the blog post!

As an example: When a customer was purchasing a VoIP PBX, the PBX vendor get angry when I requested that it be configured for DHCP so that a DHCP reservation could be used, I advised I’d prefer this method so I could change the IP when needed for maintenance or network restructuring. They tried to convince me the IP will change on a DHCP Server and the port forwarding will stop working, because they simply had no idea of what a DHCP reservation was. Ultimately when the day came where I had to change the IP and firewall rules for the PBX, I had to log a support call with the vendor since I couldn’t change the IP myself (which resulted in delays, and costs). If we were using DHCP reservations, I could have simply modified the firewall rules, modified the IP address on the reservation, and restarted the device using the buttons on the front panel (I didn’t have any other access to the device).

Just to state the obvious:

• A static IP address is an IP address that’s manually set on a NIC (Network Interface Card).
• A DHCP Reservation is a pre-set IP that’s provided by a DHCP Server, and given to a NIC when a NIC calls out to a DHCP server for an IP address.

Static IP Addresses

It’s in my opinion that for server, network, core, and all top level infrastructure, all of these devices and services should be configured with Static IP addresses.

These devices which are almost always running, and have other services that rely on them, require a set static IP that should and will not change. Typically, these IP addresses will never change, even when major changes are being made to the core infrastructure.

These addresses should always be logged, documented, and added to network topology maps.

An example of devices commonly seen with Static IPS:

• Storage (SAN, NAS)
• Network Switches, Routers, Gateways, Load Balancers
• Wireless Access Points
• Computers/Workstations using special services (or requiring firewall exceptions)

DHCP Reservations

DHCP stands for Dynamic Host Configuration Protocol, and was created to dynamically configure hosts networking configuration on the fly for easy deployment.

In it’s most simplest explanation, when a computer (or device) that is configured to use DHCP reaches out to the network, the DHCP server will assign and provide an IP address for the computer to use.

In home networks, pretty much every computer and device will get it’s IP address from the DHCP server running on the router.

In business networks, pretty much every computer and device that isn’t hosting services will get it’s IP address from the DHCP server running on one of their servers or routers.

DHCP Servers support something called a “DHCP Reservation”, which essentially allows you to provide a pre-set IP address to a specific client based on it’s physical MAC address. This means that the device will always get the same IP address and it will never change (whereas they typically do on occasion).

I’m surprised I don’t see these used more often, as they can become quite the powerful tool on the IT tool belt when used properly. I’ve listed some pros and cons below.

• Manage IP addresses (IP reservations) from a single console
• Ability to change IP addresses on the fly easily from a single console without having to log in to the device.
• Manage network topology for ROBO (Remote Office, Branch Office) remotely, easily, and efficiently.
• Manage IP addresses for 3rd party devices that you don’t normally have access to modify (tell the vendor to set to DHCP), reducing support calls for external services.
• Ability to create different PXE boot environments as each reservation can have it’s own PXE boot options assigned.
• Device must support DHCP Configuration.
• The device MUST RELY on a DHCP Server once set to use DHCP. If the DHCP Server is down, so is the device.
• If rogue DHCP servers appear on your network, it may disrupt communication (this can also happen with static IPs and conflicts).

So with the list above, DHCP reservations look pretty powerful. The next question, is where do we use DHCP reservations. Let’s finish off with the devices we’d use them on, and what use case scenarios apply.

• 2nd Level (non core) Routers and Gateways
• IoT Devices
• IP PBX Systems (VoIP, Traditional with IP Management, etc).
• Thin Clients and Zero Clients
• Remote Offices (remote sites with limited access)
• Remote Support environments
• Branch Offices
• IP Phone Networks
• Wireless LAN Access Point VLANs

DHCP Reservation Use Cases

I use DHCP reservations frequently with customers that have remote or branch offices in remote geographical areas. When supporting these users and troubleshooting issues, it’s awesome to be able to just log in to the DHCP server to change IP addresses of printers, phones, and wireless access points.

Also, when configuring, shipping, and deploying new devices to these offices, I can simply log and write down the MAC address, configure the DHCP reservation, and the device will get the IP address I’ve chosen once it’s connected to the network and powered on.

Using DHCP reservations, you can easily make big changes to these remote networks without having to be present. If you were to use Static IPs and something was misconfigured, this might cause a physical visit to the site to resolve.

If by change a vendor directly dropships equipment to the remote site, I can simply call someone at that office to get the MAC address. Most devices with a NIC (printers, MFPs, wireless access points), all usually have their MAC addresses printed on the outside of the box. With this information provided, I can login to the remote server, create a DHCP reservation, configure drivers, and push the device config out to the network.

DHCP reservations add to the whole concept of a centrally managed environment, which further helps ease of maintaining, and supporting it.

Leave a comment and let me know your thoughts!

  49 Responses to “Static IP vs DHCP Reservation”

Very good information. Thanks for sharing.

Would you create a DHCP reservation for your network switches? I have about 15 –

Typically static IPs would be used for switches, as they would generally always need to be accessible, even when a DHCP server is down.

There might be a few odd non-standard use cases where non-backbone switches may use reservations in remote sites, but I could only see this ever being used in geographically remote sites that aren’t easy to visit.

Your explanations are so easy to follow.

Thank you for not assuming that we’re all IT professionals!

Hi Stephen,

So sorry to address you as “Kevin”…my bad. I had just read your reply to Kevin.

No problem Jerry! Cheers!

I’m trying to set up parental controls via a dns server. I realized that it was possible to get around the dns server by changing the dns server on each device. I’m trying to figure out how to force all devices on my network to go through the dns server I have chosen. I’ve come across port forwarding a few times but am struggling to nail down the steps to make it work. Could you possibly help me with this? Thanks in advance!

In Christ, Kenny Sparks

Thank you for the thorough, easily understandable explanation, Kevin.

I agree whole heatedly. It’s astonishing to think that any vendor supplying network equipment wouldn’t know DHCP. I’ve known about reservations for a long while, but it’s never really been showcased as a solution. Whatever makes our lives easier I always say.

This is fantastic info, but when you are a 3rd party vendor that has the only remote access to a device, static is best. It allows for NAT IP configs as well as other VPN server options the hospitals (in my case) use. In other cases, when a reservation or reservations aren’t documented properly, remote access becomes a problem when DNS and anything else is changed. Obviously this can happen with static as well, if the hospital doesn’t notify the 3rd party of the changes, however, this is generally, at least in my teams experience not the case. Hope that improves things.

I follow basic rules for when to use static IPs and DHCP reservations: 1) Router or Core switch – Static IP 2) Server – Static IP 3) All other infrastructure is DHCP w/reservations (switches, APs, printers, cameras, DVRs, time clocks, appliances, etc)

I contemplated using DHCP for most servers, but since DHCP servers have to be static and some applications might have problems if an IP changes unexpectedly (like due to a DHCP server failure or even a bad switch vLAN change), I decided to keep all servers static.

I’ve had many vendors tell me they don’t support DHCP, but 100% of the time they don’t understand DHCP w/reservations is effectively the same as a static IP. I’ve never come across a device connected to the network that doesn’t support DHCP even though I’ve been told by a vendor on multiple occasions their equipment doesn’t support it. I do not budge on this, and force them to learn their equipment better. I’m sure something exists out there that doesn’t support DHCP, but do I really want to use something with that bad of a network implementation? What else can’t it do?

The cons are minimal and can mostly be mitigated via a robust DHCP server infrastructure. 1) DHCP server must be available – Redundant DHCP Servers make this robust 2) Nothing can interfere with requests between client and server This one is obvious, but the only problem I’ve had in the past 15 years using DHCP reservations was our MPLS provider all of a sudden stopped passing DHCP requests from one site to our data center. The work-around was to install a local DHCP server with the reservations defined until the problem was resolved. Once the provider fixed the problem, I just re-pointed the routers to the data center DHCP servers again. 3) A rogue DHCP server can cause problems. It’s pretty quick to identify this is happening and doesn’t take long to find it. If you disable or isolate unused switch ports, then this has very little chance of happening.

It’s important your lease times are long enough to give you time to respond to DHCP server problems.

The pros are massive: 1) All IPs are authoritatively documented in DHCP (minus routers and servers). This makes managing the IP space so much easier. I put in dummy reservations for servers just so DHCP includes those as well. 2) There is almost no chance of an IP conflict 3) Infrastructure setup can be done in one location (like corporate) and moved to its final destination without any reconfiguration required. It’s convenient to setup switches, APs, and printers at corporate while on the network, and as soon as you plug them in at the remote location they just work (setup the IP reservation ahead of time). 4) Reconfiguration of IP scheme is trivial. I’ve done this many times to correct poor IP schemes I’ve inherited, and by setting the lease time to 5 minutes before the change, all devices pull new IP information almost immediately. If there’s a mistake on vLANing, the correct IP will be pulled in only a few minutes once fixed. When the project is complete, set the lease times back to normal values. 5) It’s trivial to replace a device because there will never be an IP conflict. Modify the IP reservation when it’s time for the new device to be installed, and the new device will take over the IP and the old device can still be connected if necessary as it will just pull a random IP at this point (or a set IP if you want to setup another reservation). 6) The IP scope range can be used more efficiently because IPs are managed centrally on the back-end, and it’s not reliant on devices being configured with the correct IP. I never have to guess what device has what IP and wonder if something was set to the wrong IP. I can look at my DHCP server to know what’s what. 7) If you need to make a default gateway change (either temporary or permanent), it’s trivial. This has come up before because we needed to change the destination of traffic outgoing from a location temporarily while service was being performed on the primary equipment. It’s an unusual event because normal redundancy usually addresses problems like this, but I’ve had larger failures to deal with that required temporary installations to cover until repairs to utility infrastructure is completed. Once the repair is done, updating the default gateway again gets everything flowing properly.

I’m an adamant supporter/enthusiast for DHCP reservations. 🙂

Ben, you’re awesome! Thanks for contributing to the discussion! Excellent advice!

Hi Steven, If a device has a static IP address should that address be included in the DHCP Scope, and then ‘dummy reserved’ out, or should the static IP address be outside the DHCP Server Scope? Say the network is not too big – can I set a scope of 192.168.1.2 to 192.168.1.99, then Fix the IP addresses of my Printers, Accesspoints etc into the 192.168.1.100 to 192.168.1.150 range, say, which won’t require any reservations as the fixed IP devices wont request IP addresses anyway, or should I Fix the IP addresses inside the scope, and just give them reservations, so no other device is accidentally given the address belonging to a fixed device. The advantage I see for the second method is that the connected devices all exist within the DHCP scope, and can be documented. Thanks for your article – just wondering about best practice – pros and cons of the two methods.

For best practice, I wouldn’t recommend using Static IPs inside of the DHCP pool range. For example, you’d want to have your DHCP range from .100 to .199 and then have your servers in .10 to .19 and printers from .20 to .30, etc… It just avoids problems…

As for DHCP reservations, you can have those within or outside of your DHCP scope.

Cheers, Stephen

This exercise asks you to create a DHCP reservation on the current scope, to ensure one of our servers will have the same IP assigned to it. Create a reservation on your DHCP server to ensure that one of your servers (for instance SRV02) will always have the same IP assigned to it. We want to assign ip 10.1.1.200, for instance Once you create the reservation print the output of the command: Get-DhcpServerv4Reservation -ComputerName “dhcp01” -IPAddress 10.1.1.200 | fl *, (the IP is merely for illustration purposes) kindly answer me asap.

[…] Static IP vs DHCP Reservation […]

Hi, is there a way to reserve a range of IP addresses for specific manufacturers? I have 15 Hickvision security cameras, currently configured for static IP. I would like to reserve a DHCP IP range on X.X.X.180-199. So I know the cameras will always be in this scope, by the same token I could have all my Apple devices in X.X.X.150-170 … etc.

MS best practice is to use Dual DHCP servers with either fail over or load balance and use DHCP reservations vs setting static IPs now for servers. The only thing you set static is core networking / hypervisors / routers

THANK YOU! It’s sadly “acceptable” to interchange these terms. I have to just cringe and let it go, I’ve even seen a router with a “Static DHCP” settings. wtf- static – dynamic, that’s really sad.

Could you explain what “hard wired” explicitly means?!? An RJ45 port – removable jack is not hard wired! A removable is not a hard wired connection… yet so many “tutorials” interchange these as well

I believe people just use the term “hard wired” in reference to a hardware wired network connection, versus something like wireless.

One subtle disagreement: You said “The device MUST RELY on a DHCP Server once set to use DHCP. If the DHCP Server is down, so is the device.” Not quite true, as many devices can utilize a self-assignment method for addresses when no static address is configured and the device is set for DHCP service. Windows calls this Automatic Private IP Addressing (APIPA). OS X also does the same thing (not sure what it’s called there).

APIPA addresses will be self-generated in the private IP range 169.254.0.0 to 169.254.255.255, with a subnet mask of 255.255.0.0

To the uninitiated, this can be very confusing and pointless. But it’s actually pretty cool because it allows the creation of ad-hoc networks: Just plug two (or more) computers into each other, and they will have a functioning network between them. Think file sharing here for example.

The other thing is a machine with a self-assigned address can easily be found on your LAN by using IPCONFIG, a scanner, or looking at ARP tables.

Self-assigned addresses are also noteworthy in that if your computer has one, it means it cannot find a viable DHCP server on your network,

Hey Joseph,

Thanks for the post with all the information!

Great post! I could not agree more with the position taken here. DHCP Reservation plays a huge role in effect network IT management and most importantly, network performance! Those not using this method of IP assignment are truly missing out and wasting time.

[…] Information on Static IP vs DHCP Reservation ( https://www.stephenwagner.com/2019/05/07/static-ip-vs-dhcp-reservation/ ) […]

I’ve been using DHCP reserved for years as a simple way to permit clients by MAC address and block all others.

Setting appropriate and reasonable DHCP lease times for mixed type of clients — such as an hour for short-term clients versus a week for others — is often not possible on the gateway / DHCP server.

Perhaps some routers permit different lease periods for DHCP reserved clients; but from my experience both true dynamic and reserved dynamic expire at the provided period.

In the last 5 years, the D-link Wireless routers Ive worked with — and possibly other brands — often fail when the DHCP lease period expires on the DSL or cable modem. Sometimes its works; sometimes it doesn’t. In many cases the Wireless router needs to be rebooted. Which causes a mess for the connected WiFi clients.

I’m curious why the D-link isn’t notified by the DHCP server and simply gets the same address again within MICROSECONDS. Or maybe it is and the actual issue is the WiFi router is failing it’s clients.

My actiontec centerylink router uses DHCP reservations and over time the accumulation of those reservations slowed up the internet from 40 mbps down to 7mbps. By clearing reservations 7 to 40 instantly. Thoughts? Maybe I should use static in my practice.

Technically the use of reservations should not effect your internet speed.

For everything other than an Active Directory Domain Controller, I prefer to set up servers with DHCP Reservations. As you outlined, it is easier to centrally manage services you want to provide to these systems (via DHCP Options), updating addresses for whatever reason, such as if network configs need to be changed (i.e. subnet / VLAN migrations), having a central record of addresses on the network, migrating services from one server to the other while keeping the same address, etc. Also, configuring HA DHCP (High Availability) allows me to keep everything configured and provide addressing services while I do a migration, upgrade, or in the event of a failure.

In the world of printer management, if a device fails and you are replacing it with the same hardware model, simply swapping out the MAC in the DHCP Reservation, print services easily migrate without having to figure out a printer UI.

On systems that support it, I will set a “fallback” IP in the event DHCP services fail for some reason.

All of that said, some networks that I help administrate have dedicated IT staffing and sometimes they desire statics. I think due to fear of having the network crash due to a DHCP server failure (again, HA is beneficial here) and they are not comfortable with leaving the “old” way of configuring services.

For network devices, I will have a Management interface / VLAN configured with a static in a large subnet (for example, a /16) as a default VLAN. This makes routes and ACLs easier to configure and allows me to access these devices without any server-based core network infrastructure services.

Great post, and I hope more people will begin adopting the simpler design of DHCP and reservations.

Thanks for the writeup . I had a follow-on question. I always struggle with hostname resolution within my router (att). Now any programs I use will resolve it just fine (typically Putty, WinSCP, etc, even at the command line. But being a techie, I like to know why the heck it’s not working. My experience says that by setting a reservation rather than static ip, you are still utilizing DHCP, but resolution happens with DNS. So Am I missing something?

So this is a tough one because it’s dependent on the setup, hardware, and software.

If the DHCP and DNS software is connected, then by creating a DHCP reservation, it may automatically create an A HOST record in DNS for the reservation. There’s also a chance it will create an accompanying reserve DNS entry as well.

Keep in mind this all depends on the router vendor, what DHCP and DNS servers they are using, and if they are integrated.

I could be wrong, but I think some routers also use a single service/daemon that actually provides both DHCP and DNS from a single service.

Hope this helps!

Hello Stephen,

i have a client who has two physical lan networks ,in two different locations ,with the same IP Range , interconnected with a fibre optic cable. The result being a single logical network with two routers both having DHCP servers enabled and having the same IP range. This is necessary, because if in any case the optic link fails both physical networks have to operate their own individual network\ systems without interruption. But the problem is there are IP conflicts, despite DHCP reservations for specific systems in the respective routers. Certain systems get an automatic IP within the 169.254.X.X range and fail to communicate. Also there are separate Internet Connections at both locations.

Is there a work around , while maintaining the routers in the two physical locations .

I have thought about using two different logical networks with static routes assigned, but am not sure about it working. will i able to ensure communication between systems on the two different networks, as if there are on the same lan network (All the computers are windows systems, there are also Tablets and mobiles connected via wifi). But here arises another problem both physical locations have thier own servers , and the custom designed softwares requires the servers have each have a static IP that falls in the same IP range 192.168.0.X . This was set by the firm that did the software.

is there any other alternative work around.

Thanks, Anselm

There’s a big flaw in your network design.

If you’re using switches at both locations, with a fiber cable connecting them, then you should have only 1 router. Technically you could have 2 routers and it would be sloppy, but you should only have 1 DHCP server per subnet. This is why you are getting IP conflicts.

You make the comment “This is necessary, because if in any case the optic link fails both physical networks have to operate their own individual network\ systems without interruption.”. This isn’t actually necessary.

The proper configuration would be to have 2 different subnets at each location, each with their own router and DHCP. Then, route the different subnets in both locations. This would avoid any issues, put the different physical networks on their own subnets, allow you to customize IP allocation (since you can have a DHCP server on each side), and is the proper design. It would also allow you to configure custom routes for each subnet so you can specific which location uses what internet connection.

Thanks for the advice on using two different subnets. One of my concerns in doing so, is would a user on a computer on one subnet be able to browse the shared drives/folders on a computer on the other subnet , without having to manually type the IP address of the target system( Network Discovery being turned on in all the systems). Is it necessary to use a VLan for this . or i can i avoid that.

If you’re using Active Directory and/or DNS, you shouldn’t have any issues with network shares, accessing them, using them, etc… Using multiple subnets with routers is standard practice because of the limitations of how many devices or computers you can have in a single subnet.

As for your question about using a VLAN, I’m not sure why you’d want to use one, but technically you could if you had the requirement. What I would recommend would be to configure a router and route the subnets.

My company has chosen to try and mitigate security by using up all of the DHCP addresses in the scope to only allow a couple of free DHCP leases to be grabbed. If a reservation exists with a specific IP address and someone adds a computer using a static IP address with the same IP as the reservation, there will be an IP conflict. Which one will win? Which computer gets access to the network and which one just gets an error message about IP conflict and doesn’t gain access?

What vulnerability are you trying to mitigate, I’m somewhat confused by your statement or what you’re trying to achieve?

As for your question, it depends on how it’s detected or forced. Normally the computer that’s connecting 2nd will notice the conflict and decide to back off, but this can be forced. Also, there’s nothing stopping anyone from just using a different static IP and accessing the network.

Yeah, it doesn’t make much sense to me either, but my boss seems to think this ensures that he knows what machines are on our network. I personally think that something like the Cisco Identity Services Engine would be the best way to go.

This would do absolutely nothing for security, and wouldn’t provide any visibility in to what devices are on the network. DHCP is only for providing client configuration, nothing as far as network access or security.

You’d need something else like NPS or the like, which would require authentication before granting access to the network.

By the way, thank you so much for getting back to me so quickly. I really do appreciate it.

Sincerely, Chris

hello good day Sir

question. How to know if any computer has reservated ip ? note: i can not check dhcp server because i dont have acesss , any suggestions? . only i know that computer does not have ip static because check NIC

thx in advance

sorry my english is bad

Cristal clear, great expalnation and examples. Thank you, Stephen!

May I know what is the different between DHCP Reservation (active) and Reservation (inactive)?

I would need to know the exact context, but I’m assuming that an inactive DHCP reservation, is a reservation that is configured, however the client hasn’t contacted the DHCP server to retrieve it.

Whereas an active DHCP reservation, is a reservation that is active because the DHCP client has connected and retrieved it.

In the last years I have seen many and many devices changing their mac address at some point, be it an iphone with “privacy feature” enabled, to set top boxes, ip cameras etc… in such cases reserved ip gets lost, devices are still present and working but on different addresses. It gets confusing at some point. I think manufacturers or software and firmware developers should not allow such mac spoofin so easily, they give for granted that MAC are not revelant to end users but that’s not true, even a small “smart” home with plugs, TVs, smart speakers lights etc… has its complex infrastructure based on fixes addresses.

so Best Practice, my understanding and please correct me if wrong…. 1. Create a DHCP Scope that does not include Core Switches, Servers, Gateways 2. Create reservations using MAC Addresses for Printers, WAP’s, VoIP phones, cameras, Core Desktops and anything else that may want static ip and is not core infrastructure. 3. Reservations can be inside or outside the DHCP Scope,

I have one newly installed device that I cannot Ping. Created Reservation as per instructed, and still cannot get this to “talk” through the network. This is a type of PA Gateway. Installers says its my network. Suggestion to troubleshoot to get the device to “talk” through the network? I have found no reset button.

I have been using this myself for a specific use case. 1. Many homeworkers are remoting using simple hardware, to leverage the real hardware in the office for heavy graphics work. 2. Masquerading can cause issues with multiple remotes at the same time with this software (especially with double nat) that works better using direct snat/dnat translation (currently 98% gigabit throughput via double nat via a gigabit WAN & LAN setup). 3. This is a home business where they have a home private use need, but also two business networks within, that need to be not only isolated form the public network but also from the private home network who have …guests…. shall we say. This required a double NAT setup, that was still remote capable.

For this I use a /16 network for the private use, but 2 /24 networks within for business use. This also necessitates its own business wifi AP as two vlans that needed to tunnel through that private network.

Anyway, to get to the point, I needed to ensure the heavy load PCs had not only dedicated IPs but SNAT/DNAT was directly associated with those IPs (always), that would be easy to manage/administer, but would never be given to anything else. Note that the remote software used, relies upon the establised/related aspect of the firewalls and internal instigation only, via an intermediary security service. That meant ‘static reservations ‘outside of’ the DHCPs auto allocation range’, but within the network scope of the /24 network that the DHCP server(s) could access/control. Where the firewalled /24 addresses are relayed to /16 addresses on the private network that is firewalled from the public network.

I was however browsing to see if ip reservations ‘outside’ of the dhcp auto range, was accepted/standard practice and ‘working as intended’ by DHCP. So, good stuff. Thanks.

A good point made here….. https://docs.netgate.com/pfsense/en/latest/services/dhcp/mappings-in-pools.html

I guess another way to look at it is the pass the buck problem. The installer, never input a static IP, relying upon a net admin configuring DHCP reservations. The net admin, never set a static mapping in the DHCP, expecting the intaller to manually set a static one. Thats where you get the meme about the word ‘ass-u-me’. If both are done, does it matter ? Is the device going to fail to get the expected address, that someone somewhere expected it to get, as long as at least one of the above done their job properly ? 😉

Thank you for this article; it and the comments have helped clarify my thinking for my homelab.

With regards what to DHCP reserve vs what to Static IP, I would say (& I’m running) use static IPs for everything the DNS/DHCP server depends on to get running, and everything else (after that) uses DHCP reservation.

So, if a network runs everything through the internet modem/router, that is the only device with a static IP.

If a network has a router plus a core switch, and the DNS/DHCP is run from the core switch, the router & the core switch use static IPs.

Or, if DNS/DHCP is run from pihole (or adguard etc), the router, core switch, and DNS/DHCP hardware server have static IPs.

(I could go on…)

Lastly, “document” the static IPs by duplicating their configuration in the DHCP reservation.

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• Wireless Networking
• ASUS Wireless
• Asuswrt-Merlin

Static route vs manually assigned IP around DHCP list?

• Thread starter eastavin
• Start date Dec 29, 2023

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Senior Member

• Dec 29, 2023

Is there any documentation that describes the difference between using static routes to add routers behind the main unit, versus just manually assigning an IP from the DHCP list? I did find a note that says port forwarding only works with static route somewhere but after a quick test... With a manually assigned IP from the DHCP list it worked fine. So far I have not found a difference. I must have missed something?? Thanks Edward  

What you are describing isn't a "static route". You are thinking of a statically assigned address which just means that a device has an IP address that doesn't change. You can either configure a static address on the device itself, or you can assign it a static address via DHCP, based on its physical MAC address. Static routes are rules in the router to tell it where to send packets. But to answer the question you wanted to ask, if you want port forwarding to work, the device that you are forwarding to must have a known and static IP address. It doesn't how it gets that static address, either manually, or via DHCP. Port forwarding can work with a dynamic address, but you need to use tools like UPnP to create/update the rule whenever your device's address changes.  

Part of the Furniture

Wade Coxon said: What you are describing isn't a "static route". You are thinking of a statically assigned address which just means that a device has an IP address that doesn't change. You can either configure a static address on the device itself, or you can assign it a static address via DHCP, based on its physical MAC address. Static routes are rules in the router to tell it where to send packets. But to answer the question you wanted to ask, if you want port forwarding to work, the device that you are forwarding to must have a known and static IP address. It doesn't how it gets that static address, either manually, or via DHCP. Port forwarding can work with a dynamic address, but you need to use tools like UPnP to create/update the rule whenever your device's address changes. Click to expand...

bbunge said: No, static IP addresses are not assigned by DHCP. Manually Assigned addresses are. static IP addresses are assigned at the client. The OP is confusing static route with IP addressing Click to expand...

Thank you all for your replies. I was trying to discern the difference between the result of using the tab under LAN called ROUTE... where it invites you to "enable static routes" versus the tab called DHCP where it invites you to manually assign an IP. Both result in a destination that does not change, does it not? So as far as port forwarding goes either meets the need? Or did I miss something like the advantage of one over the other?  

ColinTaylor

Wade Coxon said: Static IP address assignment via DHCP is the correct terminology. Click to expand...

eastavin said: Is there any documentation that describes the difference between using static routes to add routers behind the main unit, versus just manually assigning an IP from the DHCP list? Click to expand...

eastavin said: Both result in a destination that does not change, does it not? Click to expand...

Very Senior Member

ColinTaylor said: Not necessarily. It's universally accepted that an IP address manually set in a client's network adapter settings is a "static" address. However an IP address given out by a DHCP server is called different things by different people. Asus calls it "manually assigned". Microsoft calls them " reservations ". Cisco also uses reservations, mostly in it's enterprise equipment, e.g. https://www.cisco.com/c/dam/assets/sol/sb/isa500_emulator/help/guide/ad1774415.html Click to expand...

JGrana said: TomAto Tahmahto If we really want to get into a discussion on regional differences… How does one pronounce router? Is it RowTour or Rewter? (probably needs a separate thread) ;-) Happy New Year Folks. Click to expand...

Ripshod said: Hear, hear! We're about helping people with their networks, not their personal grammar. Click to expand...

JGrana said: I suspect my friends from over the pond (and possibly across the border) would pronounce it Rooter. Click to expand...

ColinTaylor said: You are conflating two different things. No. What is the actual problem you're trying to solve? Click to expand...

eastavin said: Of course I can argue that this is what I am doing but i have accomplished it differently. This latter ROUTE method appears far more involved to setup and I was wondering if it yields some advantages that I have not thought of? Click to expand...

ColinTaylor said: You specifically don't want to do this because you want your networks to be isolated from each other. Using static routes is necessary if you want two different networks to freely communicate with each other. This would also involve turning off NAT and the firewall on the secondary router. Click to expand...

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What is dhcp (dynamic host configuration protocol).

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Tech deals: amazon fire tv, ecoflow power station, galaxy s24, and more, the best bluetooth speakers of 2024, quick links, dhcp can handle ip assignments, dhcp controls the range of ip addresses, dynamically assigned addresses are temporary, static ip addresses are necessary for some devices, key takeaways.

• DHCP automates the process of assigning IP addresses to devices connecting to a network, making it easier to connect multiple devices.
• DHCP allows you to control the range of IP addresses available for use, ensuring you can limit the number of devices connected to your network.
• While DHCP assigns IP addresses temporarily, static IP addresses are necessary for certain devices (e.g. servers) to maintain consistent connectivity and configuration.

The Dynamic Host Configuration Protocol (DHCP) is integral to networks and controls what IP addresses devices receive so they can communicate with the internet. Usually, IP assignment is automated, but if you need static IPs, familiarity with DHCP is essential.

Every device that connects to a network needs an IP address . In the early days of networking, users manually assigned themselves an IP address, but that's a cumbersome task, especially for places with many devices, such as a corporate office. DHCP, in part, automates this process, which makes connecting devices to the network far easier. DHCP servers or routers handle this process based on a set of defined rules. Most routers are set to use a 192.168.0.x range, for instance, so you'll commonly see IP addresses like this in home networks.

The process is pretty straight forward. When a client (a computer, IOT device , tablet, cell phone, etc.) connects to the network, it sends out a signal (called DHCPDISCOVER) to the DHCP server (or router). The server responds with all the rules and settings for the network and an IP address for use (a DHCPOFFER). The client acknowledges the information and asks permission to use the assigned address (a DHCPREQUEST message). Finally, the DHCP server acknowledges the request, and the client is free to connect to the network.

You can configure DHCP to control the range of IP addresses available for use. If you state that range as starting at 192.168.0.1 and the end as 192.168.0.100, then all available addresses will fall somewhere within that range. You'll never see a device assigned to 192.168.0.101. Also, bear in mind that the start IP (192.168.0.1 in this example) is reserved for the router. Some routers only list a starting address and then include an option for a maximum number of users (which determines the end address).

The upside to this is you can control how many devices connect to your network simultaneously (no more than 100 in this example). But the downside is if you set the range too small you can unintentionally prevent connection of new devices. To allow for a lower range of IP addresses, DHCP servers only lease out IP addresses to devices.

When a DHCP server assigns an IP Address, it does so under a lease system. The machine retains this IP address for a set number of days, after which it can try to renew the IP address. If no renewal signal is sent (such as a decommissioned machine), then the DHCP server reclaims the IP address to assign to another device. When the renewal signal is detected, the device retains its IP address for another set of days. This is why your IP address may appear to change from time to time if you use the ipconfig option often.

It's possible for two devices to end up with the same IP, such as a virtual machine (VM) that spends most of its time offline. The VM won't be able to send the renew signal, so its IP address will be handed out to another machine. When the VM is brought back up, it still has a record of the old IP address (especially if restored from a snapshot), but it won't be able to use that IP address since it is taken. Without that permission, it can't connect to the network until a new IP is assigned. But using dynamic IP addresses should prevent this type of scenario.

If you have a network connected printer or media server (such as a NAS unit Plex Server, or game server), it would be inconvenient for them to have their IP addresses changed. Sometimes hosted services require special configuration to function correctly. For example, a Minecraft server requires that port 25565 is forwarded , and you may have software pointing to your NAS's local IP. If the local IP of the device changes, then any rules (like port forwards) applied to it won't work anymore.

While renewal of the lease can prevent this, it's still possible for the IP address to change. If your router is restarted, due to a power outage or because you're trying to solve a pesky problem , then all Dynamically generated IP addresses may be reassigned. For those scenarios, manually assigning a Static IP address will solve the problem.

The exact process for this varies, especially as router web interfaces can change from device to device even when made by the same manufacturer. On some routers, like the Eero Mesh Router kit , this may be referred to by another term, such as IP reservation. But a static IP address still needs to conform to any range rules, if they exist. Using a current IP address as the basis for a static IP is usually the easiest thing to do. Depending on the device and its Operating System, it may be possible to set a static IP at the device end instead of through the router or DHCP server. This may be necessary if the router itself doesn't support Static IP.

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