Hi folks,

Today I had some really serious problems with my Gentoo router. I
could ping it, and all the network connections were in place and
functional, but no outside access. I looked into it and found that
the syslog was flooded with this:


Mar 22 21:25:55 localhost kernel: nf_conntrack: table full, dropping packet.
Mar 22 21:26:00 localhost kernel: printk: 11 messages suppressed.
Mar 22 21:26:00 localhost kernel: nf_conntrack: table full, dropping packet.
Mar 22 21:26:05 localhost kernel: printk: 16 messages suppressed.


These messages spanned a full 20 hours of the log. I understand that
conntrack is the connection tracking system that iptables uses. I
also understand that its maximum is something on the order of 65000
simultaneous connections. For a simple home network, I think we can
agree that I would probably never approach this number of connections
with normal use.

So my question is this: what could have caused the router's
connection tracker to overflow?
--
Dan Cowsill
http://www.danthehat.net
--
gentoo-user@(protected)