Re: [Isis-wg] Re: Inconsistent view of routers over a LAN
Cheng-Yin Lee <Cheng-Yin.Lee@ALCATEL.COM> Tue, 10 June 2003 20:43 UTC
Received: from cherry.ease.lsoft.com (cherry.ease.lsoft.com [209.119.0.109]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id QAA16980 for <ospf-archive@LISTS.IETF.ORG>; Tue, 10 Jun 2003 16:43:21 -0400 (EDT)
Received: from PEAR.EASE.LSOFT.COM (209.119.0.19) by cherry.ease.lsoft.com (LSMTP for Digital Unix v1.1b) with SMTP id <4.00A0AEE0@cherry.ease.lsoft.com>; Tue, 10 Jun 2003 16:43:22 -0400
Received: from PEACH.EASE.LSOFT.COM by PEACH.EASE.LSOFT.COM (LISTSERV-TCP/IP release 1.8e) with spool id 45203764 for OSPF@PEACH.EASE.LSOFT.COM; Tue, 10 Jun 2003 16:43:20 -0400
Received: from 192.75.23.69 by WALNUT.EASE.LSOFT.COM (SMTPL release 1.0i) with TCP; Tue, 10 Jun 2003 16:43:20 -0400
Received: (qmail 18800 invoked from network); 10 Jun 2003 20:53:01 -0000
Received: from unknown (HELO camail03.ca.alcatel.com) (138.120.105.217) by kanmx1.ca.alcatel.com with SMTP; 10 Jun 2003 20:53:01 -0000
Received: from alcatel.com ([138.120.62.63]) by camail03.ca.alcatel.com (Netscape Messaging Server 4.15) with ESMTP id HGA9K500.H6D; Tue, 10 Jun 2003 16:43:17 -0400
X-Mailer: Mozilla 4.78 [en] (Windows NT 5.0; U)
X-Accept-Language: en
MIME-Version: 1.0
References: <D2EC481073504E498A8DB9C0687E8CAF0731FE9A@EXCHANGE0-0.na.procket.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Message-ID: <3EE642E0.F617107F@alcatel.com>
Date: Tue, 10 Jun 2003 16:43:12 -0400
Reply-To: Mailing List <OSPF@PEACH.EASE.LSOFT.COM>
Sender: Mailing List <OSPF@PEACH.EASE.LSOFT.COM>
From: Cheng-Yin Lee <Cheng-Yin.Lee@ALCATEL.COM>
Subject: Re: [Isis-wg] Re: Inconsistent view of routers over a LAN
Comments: To: Tony Li <Tony.Li@procket.com>
Comments: cc: Jeff Learman <jlearman@cisco.com>, isis-wg@ietf.org, Acee Lindem <acee@REDBACK.COM>, l2vpn@ietf.org
To: OSPF@PEACH.EASE.LSOFT.COM
Precedence: list
Content-Transfer-Encoding: 7bit
Jeff, Tony, Acee, Thanks for your clarification. L2VPN WG is defining emulated LAN (and broadcast network for IP traffic) service over IP/MPLS network and some of the mechanims being defined can result in loss of communication among a subset of routers on the emulated LAN (even if all the nodes in the underlying IP/MPLS transport network are reachable). Some of the discussions have been how tolerable are routing protocols to this type of problem, if it is worth fixing some L2VPN WG mechanisms to prevent this problem, how feasible are these L2VPN solutions, are these not well-known problems ... I hope the L2VPN WG would consider these issues and requirements in the L2VPN solutions. Perhaps a more detailed understanding of how things work/don't work may help L2VPN WG develop/appreciate solutios that will work well with routers for e.g, in case of (i) below, what would an emulated LAN user observe in the routed network (is this predictable/unpredictable?) Thanks Cheng-Yin p.s I have cced l2vpn, but pls feel free to respond only to the relevant WG as is appropriate. Tony Li wrote: > > We should also point out that in case i) things are truly broken and > in case ii) the DR will not form an adjacency with A and the protocols > will be able to tell that things are broken. > > Tony > > | -----Original Message----- > | From: Jeff Learman [mailto:jlearman@cisco.com] > | Sent: Tuesday, June 10, 2003 9:29 AM > | To: Cheng-Yin.Lee@alcatel.com > | Cc: Mailing List; isis-wg@ietf.org > | Subject: Re: [Isis-wg] Re: Inconsistent view of routers over a LAN > | > | > | > | This violates the transitivity requirement stated in ISO 10589. > | You can't run ISIS on a subnetwork where this happens. > | At least, that's the theory ;) > | > | At 11:52 AM 6/10/2003, Cheng-Yin Lee wrote: > | >Hello, > | >Just got some private responses, perhaps I should clarify. > | >This is in context of an emulated LAN, and I am not > | looking for a fix in > | >routing protocols. > | > > | >Thanks > | >Cheng-Yin > | > > | >Cheng-Yin Lee wrote: > | >> > | >> Hello, > | >> What happens if for some reason Router A can't reach > | Router B, but > | >> Router C can reach A & B (and vice-versa), when Router A,B,C are > | >> connected over a broadcast network or LAN. > | >> > | >> E.g. in the case for (OSPF and IS-IS) where: > | >> i) C is the DR > | >> ii) B is the DR > | >> > | >> Thanks > | >> Cheng-Yin > Hi Cheng-Yin, > > What I've recommended in the past for these situations is to force > the routing protocol to view the underlying network as a P2MP > (Point-to-Multi-Point) network. Many vendors support this. For > example, in our implementation you'd simply configure: > > router ospf 1 > area 0 > interface backbone > network-type point-to-multipoint > o > o > < the rest of the OSPF config> > o > > Good Luck, > Acee
- Re: [Isis-wg] Re: Inconsistent view of routers ov… Cheng-Yin Lee
- Inconsistent view of routers over a LAN Cheng-Yin Lee
- Re: Inconsistent view of routers over a LAN Cheng-Yin Lee
- Re: Inconsistent view of routers over a LAN Acee Lindem
- Re: [Isis-wg] Re: Inconsistent view of routers ov… Naiming Shen
- Re: [Isis-wg] Re: Inconsistent view of routers ov… Cheng-Yin Lee