Just started getting this. I tried the following by adding it to my etc/sysctl.conf: 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 That pretty much locked things up. Then I tried another googled solution: echo 256 > /proc/sys/net/ipv4/neigh/default/gc_thresh1 echo 512 > /proc/sys/net/ipv4/neigh/default/gc_thresh2 echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh3 And adding it also to etc/sysctl.conf: net.ipv4.neigh.default.gc_thresh1 = 256 net.ipv4.neigh.default.gc_thresh2 = 512 net.ipv4.neigh.default.gc_thresh3 = 1024 Still not working. Any ideas? TIA
what is your netmask?
Thomas Dukes <tdukes at sc.rr.com> wrote: Just started getting this. I
tried the following by adding it to my
etc/sysctl.conf:
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
That pretty much locked things up.
Then I tried another googled solution:
echo 256 > /proc/sys/net/ipv4/neigh/default/gc_thresh1
echo 512 > /proc/sys/net/ipv4/neigh/default/gc_thresh2
echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh3
And adding it also to etc/sysctl.conf:
net.ipv4.neigh.default.gc_thresh1 = 256
net.ipv4.neigh.default.gc_thresh2 = 512
net.ipv4.neigh.default.gc_thresh3 = 1024
Still not working.
Any ideas?
TIA
_______________________________________________
CentOS mailing list
CentOS at centos.org
http://lists.centos.org/mailman/listinfo/centos
---------------------------------
Yahoo! Canada Toolbar : Search from anywhere on the web and
bookmark your favourite sites. Download it now!
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.centos.org/pipermail/centos/attachments/20081127/16f5075d/attachment-0003.html>
Thomas Dukes wrote:> > > *From:* centos-bounces at centos.org [mailto:centos-bounces at centos.org] > *On Behalf Of *chloe K > *Sent:* Thursday, November 27, 2008 9:10 PM > *To:* CentOS mailing list > *Subject:* Re: [CentOS] Neighbour table overflow > > what is your netmask? > > eth0 = 255.255.240.0That is 4096 addresses (256*16).> eth1 = 255.255.255.0 > lo = 255.0.0.0lo is correct. The 'whole' net127. Of which 4 addresses have ever been used (that I have encountered)....> > These don't look right except for eth1. I have made no changes to > these in about 4 years. > > Thanks > > */Thomas Dukes <tdukes at sc.rr.com>/* wrote: > > Just started getting this. I tried the following by adding it to my > etc/sysctl.conf: > > 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 > > That pretty much locked things up. > > Then I tried another googled solution: > > echo 256 > /proc/sys/net/ipv4/neigh/default/gc_thresh1 > > echo 512 > /proc/sys/net/ipv4/neigh/default/gc_thresh2 > > echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh3 > > And adding it also to etc/sysctl.conf: > > net.ipv4.neigh.default.gc_thresh1 = 256 > net.ipv4.neigh.default.gc_thresh2 = 512 > net.ipv4.neigh.default.gc_thresh3 = 1024 > > Still not working. > > Any ideas? > > TIA > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > > *Yahoo! Canada Toolbar :* Search from anywhere on the web and bookmark > your favourite sites. Download it now! <http://ca.toolbar.yahoo.com/> > > ------------------------------------------------------------------------ > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >
Thomas Dukes wrote:> Any ideas?How many entries do you have in the arp table? "arp -a | wc -l" should show you. If you really have lots of entries in there you should try to find out the reason for that. Ralph -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20081128/58e61203/attachment-0003.sig>
-----Original Message----- From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of Ralph Angenendt Sent: Friday, November 28, 2008 4:41 AM To: centos at centos.org Subject: Re: [CentOS] Neighbour table overflow Thomas Dukes wrote:> Any ideas?How many entries do you have in the arp table? "arp -a | wc -l" should show you. If you really have lots of entries in there you should try to find out the reason for that. Ralph When I ran the above, I'm not sure I'm getting a correct response. It takes serval miuntes then returns: Printk: 100 messages suppressed Neighbour table overflow Printk: 15 messages suppressed 3 This looks like the errors except for the '3'. Thanks
Thomas Dukes wrote:> > > *From:* centos-bounces at centos.org [mailto:centos-bounces at centos.org] > *On Behalf Of *chloe K > *Sent:* Thursday, November 27, 2008 9:10 PM > *To:* CentOS mailing list > *Subject:* Re: [CentOS] Neighbour table overflow > > what is your netmask? > > eth0 = 255.255.240.0Why do you have such a large subnet? There are a number of potential performance problems with such a setup. I typically only see this in large, bridged wireless campuses. Little justification for it in a wired network. (I do have lots of networking experience and knowledge, having consulted with a number of large deployments). Even with a large subnet, you should not be arping everywhere. Either two things are happening: Your system is recording every ARP request it sees ('Who has IP x.x.x.x') to avoid arping later. Bad behaviour (IMNSHO), given your network. Your system is ARPing for every IP address in the subnet to learn all of its neighbors. WHy would it do that? Unless you have some snooping software running on your system.> eth1 = 255.255.255.0 > lo = 255.0.0.0 > > These don't look right except for eth1. I have made no changes to > these in about 4 years. > > Thanks > > */Thomas Dukes <tdukes at sc.rr.com>/* wrote: > > Just started getting this. I tried the following by adding it to my > etc/sysctl.conf: > > 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 > > That pretty much locked things up. > > Then I tried another googled solution: > > echo 256 > /proc/sys/net/ipv4/neigh/default/gc_thresh1 > > echo 512 > /proc/sys/net/ipv4/neigh/default/gc_thresh2 > > echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh3 > > And adding it also to etc/sysctl.conf: > > net.ipv4.neigh.default.gc_thresh1 = 256 > net.ipv4.neigh.default.gc_thresh2 = 512 > net.ipv4.neigh.default.gc_thresh3 = 1024 > > Still not working. > > Any ideas? > > TIA > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > > *Yahoo! Canada Toolbar :* Search from anywhere on the web and bookmark > your favourite sites. Download it now! <http://ca.toolbar.yahoo.com/> > > ------------------------------------------------------------------------ > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >