Hi, all When use Centos 6.5,kernel version 2.6.431, I have continuous messages of "Neighbour table overflow" in messages. I have modified the gc_thresh1(512) , gc_thresh2 (2048) gc_thresh3 (4096) in /proc/sys/net.. path, But the messages occurs occasionally. some forum saied: They are probably realted to a kernel bug where the thresholds are in fact only half of the value that is set. See http://patchwork.ozlabs.org/patch/170385/ --- I didn't figure it out whether it is a bug and it is fixed . Why did this happen? Who can give me hand. Thanks.