[CentOS-virt] Xen domU default gateway missing/ARP table full
kbass at kenbass.com
Thu Nov 19 18:47:33 UTC 2009
Christopher Hunt wrote:
> I think Pasi's on to something there, I bet the GATEWAY command
> in ifcfg-eth0 is mistyped or has a syntax error. In the interem,
> however, a better hack might be to move the route statement from
> rc.local, which only runs at boot, to
> /etc/sysconfig/network-scripts/route-eth0 . That will enable the
> network service to restart or the eth0 interface to downup without
> removing the default route.
Thanks for this tip. I removed the GATEWAY and GATEWAYDEV from
/etc/sysconfig/network which got rid of the initial (incorrect route)
default via 192.168.144.6 dev eth0 onlink
to the /etc/sysconfig/network-scripts/route-eth0
Note the use of the 'onlink' option. It appears to be working fine
without the arp traffic.
I guess I thought this was a more common configuration when using Xen in
a routed configuration. I'm not sure if the network scripts allow a
mechanism to add the 'onlink' option so that GATEWAY/GATEWAYDEV
specified are actually used. Grepping through the network-scripts does
not yield anything.
If other people are using this in the same way I am, you will need to do
this change or else there will be all the unnecessary arp cache activity
for every single ip address which might fill up your arp table.
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