Re: [nsp] Trying to decide on IGP

From: Jon Lewis (jlewis@inorganic5.fdt.net)
Date: Fri Jul 31 1998 - 02:26:15 EDT


On Thu, 30 Jul 1998, Danny McPherson wrote:

> One of the primary purposes for the creation of OSPF areas was to
> provide a mechanism that allows for route summarization between areas so
> that intra-area route oscillation doesn't effect the entire routing
> domain.

That's one of the things I want. A remote POP shouldn't care what's
happening on a distant LAN.

> The OSPF subordinate command "area [area-id] range [address mask]" is
> used for inter-area summarization. The OSPF subordinate
> "summary-address [address mask]" command is used for external route
> summarization (i.e., redistribution).

I can't seem to get that working either. On RTA, I put
 area 1 range 209.212.145.0 255.255.255.0

with the idea that RTA would receive 209.212.145.0/24 and subnets within
209.212.145.0/24 from RTB, and RTA would tell the rest of area 0 only
about 209.212.145.0/24. What I get is RTA tells the rest of area 0 about
an inter-area route for 209.212.145.0/24 as well as E2 subnet routes for
subnets within 209.212.145.0/24.

While poking around in the router ospf subcommands, I did find something
very interesting. Cisco OSPF supports distribute lists which may be
applied to input or output per interface. That may be the only way I can
get what I want out of OSPF. i.e. On RTB, I put
 distribute-list 1 in Serial0
and an access-list 1 that denies all. This stops all the area 0 subnet
routes from getting into area 1. I could do similar things on RTA...but
this doesn't seem the right way to get what I want.

------------------------------------------------------------------
 Jon Lewis <jlewis@fdt.net> | Spammers will be winnuked or
 Network Administrator | drawn and quartered...whichever
 Florida Digital Turnpike | is more convenient.
______http://inorganic5.fdt.net/~jlewis/pgp for PGP public key____






This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:13:14 EDT