Linux Netfilter discussions
 help / color / mirror / Atom feed
From: Eray Aslan <eray.aslan@caf.com.tr>
To: netfilter@vger.kernel.org
Subject: Re: Ipsec/L2tp with NETKEY
Date: Sat, 04 Jul 2009 07:14:56 +0300	[thread overview]
Message-ID: <4A4ED740.9050104@caf.com.tr> (raw)
In-Reply-To: <1246666906.5753.31.camel@localhost>

On 04.07.2009 03:21, Martin wrote:
[...]
> Here is a diagram, just for fun ;)
> 
> MS-client ==== /ext interface/ Linux GW /internal interface/ ==== LAN
> 
> 
> What I see is that user completes ipsec auth, and then tries to connect
> to the l2tpd's port (7101) on the external interface, and then I must
> accept connections in that port, or the vpn connection fails.
> 
> 
> Any suggestions how to let connections on udp 1701 only to connections
> before authenticated by ipsec?

On the openswan machine, mark the ESP packets and accept only marked
packets to l2tpd daemon:

# iptables -t mangle -A PREROUTING -i $EXT_INT -p 50 -j MARK --set-mark 1
# iptables -A INPUT -i $EX_INT -m mark --mark 1 -j ACCEPT
# iptables -A INPUT -i $EX_INT -p udp --dport 1701 -j DROP

-- 
Eray

  reply	other threads:[~2009-07-04  4:14 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-04  0:21 Ipsec/L2tp with NETKEY Martin
2009-07-04  4:14 ` Eray Aslan [this message]
     [not found]   ` <114b7d1a0907052027y1204f945s4d9b5ea7032d6b13@mail.gmail.com>
2009-07-06  7:04     ` Eray Aslan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4A4ED740.9050104@caf.com.tr \
    --to=eray.aslan@caf.com.tr \
    --cc=netfilter@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox