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From: Gavin Hamill <gdh@acentral.co.uk>
To: netfilter@lists.netfilter.org
Subject: Re: comments about lokkit default script
Date: Fri, 12 Sep 2003 09:02:41 +0100	[thread overview]
Message-ID: <200309120902.41066.gdh@acentral.co.uk> (raw)
In-Reply-To: <Pine.LNX.4.44.0309120210280.1054-100000@Chrestomanci>

On Friday 12 September 2003 07:11, Faheem Mitha wrote:
> Dear People,
>
> Are the lines
>
> iptables -A RH-Lokkit-0-50-INPUT -p udp -m udp -s 207.69.188.18*
> --sport 53 -d 0/0 -j ACCEPT
>
> allowing through the DHCP connection? The 207.69.188.18* are
> Earthlink servers, they look like nameservers.

Your second hunch is right - they are for Eathlink's nameservers, since that's 
what will be defined in /etc/resolv.conf... DNS lookups reply using a UDP 
source port of 53, hence the lines added by lokkit..

I would be wary of the fact that DHCP (which uses UDP ports 67 and 68) is 
currently blocked, so if you start to get connection problems in the near 
future, you'll know why - you should probably see messages from your DHCP 
client that it was unable to renew the lease...

iptables -A INPUT -p UDP -i eth0 --dport 67 --sport 68 -j ACCEPT

is what I use to ensure that the DHCP traffic is permitted from the outside 
world.

Cheers,
Gavin.


  reply	other threads:[~2003-09-12  8:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-09-12  6:11 comments about lokkit default script Faheem Mitha
2003-09-12  8:02 ` Gavin Hamill [this message]
2003-09-12 17:26   ` Faheem Mitha
2003-09-12 18:38 ` Stephen Smoogen
2003-09-12 19:01   ` Faheem Mitha
2003-09-12 19:36     ` Stephen Smoogen
  -- strict thread matches above, loose matches on Subject: below --
2003-09-11 15:10 Faheem Mitha

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