comments inline At 12:07 PM 1/4/2002 -0500, Howard C. Berkowitz wrote: > >Multi-area ISIS is really a CLNS topic. It is indeed not recommend > >that one run multi-area for IP only routing. Some use in transition > >networks may take place, but your better to simply interconnect with > >a proper L2 backbone than merge areas. > >First, let me be sure we are talking about the same thing. I think of >multi-area as implying a backbone. Are you using it in the sense of >multiple area identifiers in a level 1 area?
I will agree that the more recent use of the term multi-area implies a ISIS domain with multiple areas connected by a backbone. In this case the discussion is about have a single IS participate in multiple L1 areas (ie multiple area ID's as you suggest) > > > >The command clns routing is only required if you intend to route > >clns. For IP only environments, it is not needed. In IP only, you > >configure one NET per ISIS instance, and one ISIS instance per L1 > >area you intend to form adjacencies within. The configs your > >looking at on CCO likely include the command clns router isis on > >each interface. I doubt there are many IP only multi-area configs > >on CCO given it is not a recommended practise. > >The main application I've seen, for which there are some CCO >documents, are telco applications when you are merging the CMIP >infrastructure for several central offices or SONET control points, >in order to reduce the requirement for L2 routers. Henk Smit indicates in a NANOG presentation that at times, some telco resident ADM's may have had area sizing limitations thereby necessitating the use of numerous small areas. Without multi-area support, a similar number of routers would be required to properly interconnect these areas. I expect He and You are describing a similar usage. >Of course, CCIE lab usage and best current practices often are >orthogonal at best, and in different space-time continuua at worst. >:-) > > > > >Pete > > > > > >At 09:32 AM 1/4/2002 -0600, Michael C. Popovich wrote: > >>I have double checked on Documentation CD regarding IS-IS and the need > >>for CLNS. Peter is definitely right in the fact that CLNS is not > >>required to route IP using IS-IS. This question is for Peter and anyone > >>else with a good understanding of IS-IS. > >> > >>Reading through the Documentation CD on Integrated IS-IS I have a > >>question regarding multi-area. The way I read it I am assuming that if > >>you implement a multi-area IS-IS solution then you in fact do need to > >>enable CLNS routing. Is this true? The examples given in the > >>Documentation CD show that a single area IS-IS network doesn't need CLNS > >>routing but in the multi-area scenario they have CLNS routing enabled. > >>This isn't specifically addressed but I assume with the need for > >>different areas using different NET addresses requires the CLNS > >>protocol. > >> > >>Please correct me if I have misinterpreted this. > >> > >>Thanks, > >> > >>Michael Popovich Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=30960&t=30957 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
