From: Peter van Oene (pvo@usermail.com)
Date: Fri Sep 20 2002 - 21:51:09 GMT-3
I think folks grasp the process vs Area ID concept. However, the actual
use and relevance of area ID's is not entirely clear. My understanding is
that LSA's are carried in LS Update packets. The LSA's themselves do not
have an area-id field, however, the router can discern based upon logical
receiving interface or possible LS update area-id to which area an LSA is
relevant. This is mostly important on multi-access segments where a router
might receive a LSU for an Area for which is it not a part of.
However, with respect to the original question, multiple areas with the
same area-id will not create routing issues unless you have overlapping
area-ranges which will result in ABR's representing more of the topology
than they can actually reach.
Pete
At 04:17 PM 9/20/2002 -0600, Joe Martin wrote:
>Yes, it seems some people are confusing the Process ID with the Area ID.
>
>The process ID is stated when enabling OSPF or when entering an existing
>OSPF process. The process ID is only locally significant.
>
>router(config)#router ospf 100 <--- this is the Process ID
>
>The Area ID is not locally significant or OSPF would never work. The area id
>is carried in the LSA. This is how you can see all areas in your OSPF
>internetwork with the "sh ip ospf database" command.
>
>Someone PLEASE correct me if I'm wrong.
>
>Joe
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>Joseph Rinehart
>Sent: Friday, September 20, 2002 3:13 PM
>To: ccielab@groupstudy.com
>Subject: Re: OSPF area ID (big fight at work)
>
>
>I assume by area ID that you mean process id (e.g., router bgp 100), and if
>that is true yes the process ID is local to the router only. Area id (area
>0, area 10, etc), is definitely not local to the router or OSPF would never
>work.
>
>Can you clarify?
>
>Joed
>----- Original Message -----
>From: "Rick" <ccie_2003@hotmail.com>
>To: "Ccielab (E-mail)" <ccielab@groupstudy.com>
>Sent: Friday, September 20, 2002 11:49 AM
>Subject: OSPF area ID (big fight at work)
>
>
> > Can someone tell me that I can use the same OSPF area multiple times in
>the
> > same process as long it is talking to area 0. The area ID is not carried
>in
> > the LSA header.
This archive was generated by hypermail 2.1.4 : Mon Oct 07 2002 - 07:43:58 GMT-3