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From: Jeffrey Laramie <JALaramie@Loudoun-Fairfax.com>
To: netfilter@lists.netfilter.org
Subject: External IP addresses on internal network
Date: Tue, 26 Aug 2003 11:57:08 -0400	[thread overview]
Message-ID: <3F4B8354.7040903@Loudoun-Fairfax.com> (raw)

Hi all,

I recently updated my configuration by modifying one of my filter INPUT 
rules to specify source IPs coming in from the LAN:

iptables -t filter -A INPUT -p all -i $LAN_Interface -s $LAN_IP_Range -j 
Lan-Host

Packets not meeting this condition (among others) are logged and 
dropped. The intent is to catch any internal packets coming from an 
external IP address. No sooner did I load this rule when I started 
logging packets with an AOL IP address coming from the LAN interface 
going to port 53. I have a small LAN with only a handful of PCs which I 
configured myself, so I'm a bit puzzled.

Have I configured this wrong? Several users connect to AOL through the 
firewall so that's a possible cause, but I don't know why an AOL program 
would spoof IPs. Thoughts?



             reply	other threads:[~2003-08-26 15:57 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-08-26 15:57 Jeffrey Laramie [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-08-26 22:43 External IP addresses on internal network George Vieira
2003-08-27  1:10 ` Jeffrey Laramie
2003-08-27 16:54   ` Jim Carter
2003-08-27 18:50     ` Jeffrey Laramie
2003-08-28 14:19       ` Chris Brenton
2003-08-28 15:43         ` Jeffrey Laramie
2003-08-28 14:56       ` Ramin Dousti
2003-08-28 16:21         ` Jeffrey Laramie
     [not found]         ` <3F4E2844.2050108@Loudoun-Fairfax.com>
2003-08-28 18:17           ` Ramin Dousti
2003-08-28 19:24             ` Jeffrey Laramie
2003-08-28 15:52       ` Michael J. Tubby B.Sc. (Hons) G8TIC
2003-08-28 16:19         ` Jeffrey Laramie

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