Neighbour table Overflow

myguest · 01-05-2005, 05:25 AM

I getting the following error message on the linux box

Neighbour Table Overflow

This is slowing down the network and most of the service are now not running
It seems once i remove the network cable for the the internal network this messages stops coming out and resurfaces once i plug it in

i am running Redhat 9

Capt_Caveman · 01-10-2005, 11:29 PM

You might have some luck increasing the garbage collection values in /proc/sys/net/ipv4/neigh/default/gc_thresh*

If there aren't more than 128 hosts on the LAN you're plugged into, then you likely have some kind of networking issue, like 2 machines with the same hostname or an infected machine spewing out false ARP entires. Either way, fire up tcpdump/ethereal and see if the traffic looks abnormal.

Blaise · 02-24-2006, 04:03 PM

I am running Debian Sarge with linux-2.6.8-2-386 on my router/firewall/proxy and have the same problem. I try changing values of /proc/sys/net/ipv4/neigh/default/gc_thresh* and droping udp 1434 as pe2338 said but "neighbour table overflow" message continue. Does any one have yet a working solution?
Regarsd!

piforever · 02-24-2006, 06:17 PM

>>Neighbour Table Overflow

I hate to be your neighbour

asnani_satish · 08-18-2010, 10:19 PM

Neighbour Table Overflow occurs when there are two many ARP requests which the server is not able to reply. If u hv a huge flat network then the only solution is to increase the threshhold values in /etc/sysctl.conf

Add following lines to /etc/sysctl.conf (redhat)

net.ipv4.neigh.default.gc_thresh1 = 4096
net.ipv4.neigh.default.gc_thresh2 = 8192
net.ipv4.neigh.default.gc_thresh3 = 8192
net.ipv4.neigh.default.base_reachable_time = 86400
net.ipv4.neigh.default.gc_stale_time = 86400

and restart the machine

win32sux · 08-19-2010, 12:44 AM

asnani_satish, please don't resurrect dead threads.

Check the dates before you post.