R7000 DHCP creating multiple IP addresses for one device

[fcol]

I noticed that my R7000 is creating multiple IP addresses for an Apple Airport Extreme (3rd gen) and an Apple Airport Express (2nd gen).  When I view the Access Control list, it shows both devices eating up all the available DHCP addresses.  For example, the Express is showing 192.168.254.2, 192.168.254.3, 192.168.254.4, etc but the associated MAC addresses are all the same.  Both are wired into the router and have been assigned static IP addresses.  If I ping one of the "extra" IP addresses (using Terminal in OSX), I see this (where 192.168.254.85 is the static address):

PING 192.168.254.2 (192.168.254.2): 56 data bytes

36 bytes from 192.168.254.85: Redirect Host(New addr: 192.168.254.2)

If I reboot everything, it clears things up temporarily.  But over time, these two Apple devices will start using up all of the available DHCP addresses.  I've tried toggling the "Disable IGMP Proxying" checkbox.  And I also changing the RIP version to RIP_1.  Both of the Apple devices are set up in Bridge Mode. 

I can't tell if this is actually hurting anything except that new devices can't connect since there are no available IP addresses.  I noticed this about a week ago and just updated the router firmware to V1.0.5.48_1.1.79.  However, the problem is still persisting.

[Retired_Member · Accepted solution]

Glad it's working again,

I think static and reserved get confused more often than not. Some think they are the same which they are not. I believe using address reservations is the best way to avoid problems on SOHO networks, If you want to assign same IP's to certain devices. This also let's you leave all devices to DHCP  when on home network they are assigned a specific IP and when traveling you don't have to change settings.

I use 30 reserved addresses and the DHCP works fine and doesn't need any special settings to avoid the reserved IP's.  Not sure I understand the setttings you selected for the two apples But, the thing to remember is ONLY one DHCP server per network.

[Retired_Member]

suggest you use r7000 default settings except for WIFI

[fcol]

All of the router functions were originally set to their defaults except that I had assigned static IP's for some of my devices.  Then I noticed the multiplying IP addresses for those two Apple devices.  After that, I assigned static IP's to them but that didn't help.  Then I updated the router firmware.  Then I started messing with the other settings (IGMP and RIP_1) based on some web searches.  

I suspect that this problem has been happening since I bought the router a few months ago.  Every now and then, devices weren't connecting so I would reboot the router.  Looking back, all of the IP addresses in my DHCP range must have been used up and rebooting the router cleared things up (temporarily).  

The router's log file isn't showing anything unusual.

[Retired_Member]

Seems odd that a device with a properly configured static IP would even send a request for an IP. Did you change the  LAN TCP/IP setup?  The router is capable of over 200 IP's so if your running out as you say then I suspect your apples are misconfigured. Leave the RIP version disable too.

I've had no problems using address resevations for 30 devices    .2 ~.30 & .99 for AP You might give it a try

[fcol]

I think narrowed it down to the Airport Extreme.  I unplugged it and I'm not seeing multiple IP addresses for the Airport Express.  When I switched both Apple devices to static IP (they were running for months with dynamically assigned IPs), I actually did not go into their settings (I left them to connect via DHCP and set the router to assign the static address*).  Keep in mind that the multiple IP address thing was happening before I switched them to static.  But in any case, it seems like the Aiport Extreme is doing something strange.  When I reintroduce it back into the network, I will assign it a proper static address.

Thanks for your help, searay.

* As an aside, I have a number of devices where I assign static IP via the router but I leave their individual device settings to connect via DHCP.  I suppose this is poor practice?  Are you supposed to assign the static IP in both the router and device?  If you were to only change to static in one, would you choose router or the device?  With some devices, I can't get into their TCP/IP settings so that's why I always just assigned the static in the router and left the device to connect via DHCP.  It also helps in situations where I want the static IP at home but am able to grab dynamic IP when elsewhere.

[Retired_Member · Accepted solution]

Glad it's working again,

I think static and reserved get confused more often than not. Some think they are the same which they are not. I believe using address reservations is the best way to avoid problems on SOHO networks, If you want to assign same IP's to certain devices. This also let's you leave all devices to DHCP  when on home network they are assigned a specific IP and when traveling you don't have to change settings.

I use 30 reserved addresses and the DHCP works fine and doesn't need any special settings to avoid the reserved IP's.  Not sure I understand the setttings you selected for the two apples But, the thing to remember is ONLY one DHCP server per network.

[TheEther]

Technically, you can use more than one DHCP server per subnet, so long as their address ranges do not overlap.  This could be necessary if there are more than 32 wireless clients on a wireless band, because that is the limit on Nighthawks.  As IoT (Internet of Things) devices, like thermostats, IP cameras, streaming video players, home stereo receivers and home automation controllers, become more popular, this limit can be easily exceeded. 

[fcol]

searay- Thanks for pointing out the difference between reservations and static IP.  

I was able to introduce the Airport Extreme and prevent it from getting multiple IP addresses assigned to it.  I set a static IP for it in its own settings.  And then I also reserved that address in the Netgear router.