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My DD-WRT router has lost its mind!

(Caveat: technically neither of these devices are "routing". I'm going to call them routers anyway.)

I just set up two DD-WRT routers, one as a WAP (working fine) and one in Client Bridge (routed) mode (the problem). Not long after setup I started seeing IP address conflicts on other machines. The event log always points the finger at my Client Bridge router's MAC address.

Neighbour table overflow

The log on my router is flooded with Neighbour table overflow errors. These start a minute or two after boot. The network is rather large, with +200 IP addresses being used in this subnet. The other router shows no such errors.

Mass ARP requests from

I'm also seeing constant ARP requests (with the problem router's MAC address) from Seems like it's bugging everything on the network for its MAC address and then promptly forgetting it (or never receiving a response).


Model: Buffalo N600

Firmware: DD-WRT v24SP2-MULTI (03/21/11)

Wireless Mode: Client Bridge (routed)

brctl show output:

bridge name      bridge id            STP enabled     interfaces
br0              80000.106f3f289f6a   no              eth0

Neither device is configured for DHCP, however there does seem to be a rogue DHCP server on the network right now...

I'm not sure what configuration details are relevant and I'd rather not have comments flooded, so just ping me in this chat if you want to know something.

Why is my router stealing IP addresses and how can I stop it?

share|improve this question
What are you bridging to? Also is there only 1 dhcp server per subnet? I assume there is another subnet before the gateway as you are using a bridge to something... Also on a 200 pc network you should see a constant stream of ARP requests, unless you are running wireshark on the edge device you won't see the responses. – Kyle Dec 5 '12 at 17:25
Also so I know what options you have selected did you do everything in this list for the AP? It doesn't hurt for me to make sure you don't have both the AP and Bridge setup as dhcp servers. – Kyle Dec 5 '12 at 17:26
Same here. Did you find out anything? – Max Ried Jul 19 at 20:29
@MaxRied In hindsight, yes! The subnet mask was way off, and the networking scheme wasn't in private space to begin with. I suspect the router was trying to build a table for the entire space. I never did get the router to work, but fixing the subnet mask might've helped. – Tanner Faulkner Jul 21 at 17:45
@TannerFaulkner Unfortunately this doesn't apply to me :( Mine sends valid arp requests - valid but from – Max Ried Jul 21 at 17:47

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