Subject: L2TP Redundency

From: "Geping Chen" <[email-masked]>
Date: Fri, 23 Feb 2001 13:18:55 -0800

Hi, 

I have a question,

After L2TP tunnels are established, the IP interface of the LAC 
goes down, is it still OK to maintain all these L2TP tunnels by 
using another IP interface of the LAC? Does the sender IP address
matter?

If anyone can provide me some information about this, I will greatly
appreciate it.

Geping

---

From: "Joseph D. Harwood" <[email-masked]>
Date: Fri, 23 Feb 2001 18:14:21 -0800

L2TP RedundencyI'm not too familiar with L2TP's checks, but if you're using
IPsec to secure your L2TP connection, one of the inbound selectors at the
LNS/Security Gateway is most likely source address.  If this changes, the
inbound selector check will fail and the L2TP packets will be discarded.

Best Regards,
Joseph D. Harwood
[email-masked]
www.vesta-corp.com

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On Behalf Of
Geping Chen
  Sent: Friday, February 23, 2001 1:19 PM
  To: [email-masked]'
  Subject: L2TP Redundency

  Hi,

  I have a question,

  Geping

---

From: Motonori Shindo <[email-masked]>
Date: Sat, 24 Feb 2001 16:52:24 +0900 (JST)

Geping,

According to the RFC2661, once the IP address is determined, it MUST
NOT change. 

8.1 L2TP over UDP/IP

   L2TP uses the registered UDP port 1701 [RFC1700]. The entire L2TP
   packet, including payload and L2TP header, is sent within a UDP
   datagram. The initiator of an L2TP tunnel picks an available source
   UDP port (which may or may not be 1701), and sends to the desired
   destination address at port 1701.  The recipient picks a free port on
   its own system (which may or may not be 1701), and sends its reply to
   the initiator's UDP port and address, setting its own source port to
   the free port it found. Once the source and destination ports and
   addresses are established, they MUST remain static for the life of
   the tunnel.

From: "Geping Chen" <[email-masked]>
Subject: L2TP Redundency
Date: Fri, 23 Feb 2001 13:18:55 -0800
Message-ID: <[email-masked]>

> If anyone can provide me some information about this, I will greatly

=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=--=
 +----+----+     
 |.. .|    |     Motonori Shindo
 |_~__|    |     
 | .. |~~_~|     Sr. Systems Engineer
 | .  |    |     CoSine Communications Inc.
 +----+----+     
 C o S i n e     e-mail:  [email-masked] 
Communications
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