Re: [gentoo-user] Gentoo router: Conntrack table full

[Dan Cowsill]

On Sat, Mar 22, 2008 at 11:22 PM, Andrey Falko <ma3oxuct@×××××.com> wrote:
>
> On Sat, Mar 22, 2008 at 11:16 PM, Dan Cowsill <danthehat@×××××.com> wrote:
>  > 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@l.g.o mailing list
>  >
>  >
>
>  What type of 'net services do you run between your home network and
>  the outside? Is there a possibility that someone out have put a denial
>  of service attack on you?
>  --
>  gentoo-user@l.g.o mailing list
>
>

I have SSH to a server, two open ports for bit torrent connections and
a few ranges for DCC transfers from irc.

The possibility of a DoS attack is pretty real, I imagine.  Is there
any way I could be sure?

-- 
Dan Cowsill
http://www.danthehat.net
-- 
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