RE: OSPF Cost Question

Petr,

Thanks! I was taking a 10,000 ft view. I was doing a "sh ip ospf database
adv-router x.x.x.x" to see all of the LSA types being sent by a neighbor.

Mike

> Date: Thu, 19 Aug 2010 13:11:20 -0700
> Subject: Re: OSPF Cost Question
> From: petr_at_internetworkexpert.com
> To: mkiefer74_at_hotmail.com
> CC: ccielab_at_groupstudy.com
>
> Mike,
>
> You probably missed the output from "show ip ospf database router"
> command. By inspecting the router LSAs you will see metrics associated
> with every link, e.g.
>
> LS age: 544
> Options: (No TOS-capability, DC)
> LS Type: Router Links
> Link State ID: 180.4.2.2
> Advertising Router: 180.4.2.2
> LS Seq Number: 80000024
> Checksum: 0x2E09
> Length: 72
> Number of Links: 4
>
> Link connected to: a Transit Network
> (Link ID) Designated Router address: 180.4.29.2
> (Link Data) Router Interface address: 180.4.29.2
> Number of TOS metrics: 0
> TOS 0 Metrics: 1
>
> Link connected to: another Router (point-to-point)
> (Link ID) Neighboring Router ID: 180.4.1.1
> (Link Data) Router Interface address: 180.4.12.2
> Number of TOS metrics: 0
> TOS 0 Metrics: 64
>
> Notice the "TOS 0 Metrics" associated with the link. It is not very
> easy to reverse map the OSPF Link-IDs to the actuall links, and hard
> to figure the best paths out of this information (OSPF runs SPF to
> accomplish this, after all). Keep in mind that the metric field is 16
> bit and therefore cannot exceed 65535. Of course, only one metric is
> supported in OSPFv2, even though there are multi-topology extensions
> to OSPF that reuse the ToS metric fields.
>
> HTH
> --
> Petr Lapukhov, petr_at_INE.com
> CCIE #16379 (R&S/Security/SP/Voice)
>
> Internetwork Expert, Inc.
> http://www.INE.com
> Toll Free: 877-224-8987
> Outside US: 775-826-4344
>
>
> 2010/8/19 Mike Kiefer <mkiefer74_at_hotmail.com>:
> > I have a pretty good understanding of how to read and understand the OSPF
> > database thanks to Narbik's bootcamp a few weeks back. As far as I know,
there
> > is no way to see costs associated with each link in the link state
database.
> >
> > Is there any way to see the advertised cost with a show command, or is
that
> > strictly a debug thing?
> >
> > I want to see the "loser" routes the didn't have a cost low enough to make
it
> > into the routing table.
> >
> > Thanks,
> >
> > Mike
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Thu Aug 19 2010 - 15:20:55 ART