Re: nf_conntrack_count versus '/proc/net/nf_conntrack | wc -l' count

[Patrick McHardy <kaber@trash.net>]

Douglas Diniz wrote:
> I'm facing the same problem. I'm working in a embedded system with
> kernel 2.6.20-6. When I send a ping (or any other protocol) through
> eth0 to eth1 (or vice versa) the conntrack count isn't decremented. If
> I send the ping through any other interface (eth0 to wifi, eth1 to
> wifi, wifi to eth0 and wifi to eth1) I have no problem.
> The problem seems to be only between the ethernet interfaces.
> I debug the netfilter and I saw that when the problem occurs the "use"
> variable inside conntract structure in > 1, so this variable is only
> decremented by 1, not reaching in 0, and then the destroy_conntrack
> function is not called.
> 
> So I think that the problem is more low level, and some events aren't
> reaching netfilter, and the "use"variable isn't decremented properly.
> 
> This could be a problem with the ethernet driver?

Yes, although you'd likely notice other effects like running
out of memory if it was leaking the packets.