From: Scott King (scking@xxxxxxxxx)
Date: Sat Feb 10 2001 - 19:31:06 GMT-3
Ya,
I probably should have worded that differently. What I meant was that
all of the routes on the OSPF network were /29 except for the two
point-to-point subinterfaces in the FR net, which were /30. All of the
subnets on the IGRP side were also /29, which meant that IGRP would
recognize the /29 subnets from OSPF but not the /30s. I summarized the
two /30s into one /29 and redistributed THAT into IGRP. After that, the
scenario worked.
OSPF summary-address is NOT only for summarizing outside routes. It is
also for summarizing between areas--a very helpful trick. If you can
summarize an entire area into one route, you can reduce the size of the
routing table on the core. This is common practice. If one subnet goes
down at the access level you won't have core routers participating in
convergence (since they don't know about the subnet, just the supernet).
Regards,
R. Scott King
Network Consulting Engineer
Cisco Systems, Inc.
Advanced Network Support - SP
9155 E. Nichols Avenue Suite 400
Englewood, CO 80112 USA
919.949.8425
Ya Wen wrote:
>
> Scott:
>
> Can you share how you summarize the OSPF route and then redistribute into
> IGRP domain? The OSPF summary-address command is only used to summarize
> from outside domain into OSPF domain, am I right?
>
> Thanks!
>
> -Ya
>
> On Sat, 10 Feb 2001, Scott King wrote:
>
> > Solution to the problem was to summarize OSPF into IGRP. What a
> > sophmoric mistake! I need to stop doing lab exercises so late at
> > night.....
> >
> >
> > Scott
> >
> > Sandy Thielamay wrote:
> > >
> > > What ip addresses are you using ? Are you using a class A and
> > > subnetting...remember you are dealing with classful and classless protoco
l.
> > > Remember FLSM and VLSM..If you are using any of the scenario above I wou
ld
> > > summarize the OSPF routes on the ASBR and see what happen when it goes in
to
> > > IGRP. Make sure when you are redistributing you are following the protoco
l's
> > > metric..i.e igrp bandwith,delay etc.....
> > >
> > > Hope this help
> > >
> > > Cheers,
> > >
> > > Sandy
> > >
> > > -----Original Message-----
> > > From: Scott King
> > > To: ccielab@groupstudy.com
> > > Sent: 2/9/2001 5:13 PM
> > > Subject: OSPF-IGRP Redist.
> > >
> > > Hey All,
> > >
> > > Setup is this:
> > >
> > > r5---fr---r4---hdlc---r1---token---r3
> > >
> > > Between r5 and r4 is OSPF area 0. Between r4 and r3 (including r1) is
> > > IGRP AS 10. Two-way redistribution on r4. Routes attached to r3 show
> > > up in r5's table, but I can't ping them.
> > >
> > > Suggestions?
> > > --
> > >
> > > R. Scott King
> > > Network Consulting Engineer
> > > Cisco Systems, Inc.
> > > Advanced Network Support - SP
> > > 9155 E. Nichols Avenue Suite 400
> > > Englewood, CO 80112 USA
> > > 919.949.8425
> > >
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