From: Nathan Chessin (nchessin@cisco.com)
Date: Fri Nov 08 2002 - 18:52:19 GMT-3
You can do this statically, but you don't know which OSPF RID should match
which BGP RID necessarily. A decent workaround is the confederations
solutions, because this basically makes everything eBGP like and gets rid of
iBGP issues.
Nate
> -----Original Message-----
> From: KHAN, IFTIKHAR A [mailto:IKHAN@scana.com]
> Sent: Friday, November 08, 2002 1:02 PM
> To: 'Nathan Chessin'; 'ying c'; 'Conrad Bullock';
> ccielab@groupstudy.com
> Subject: RE: OSPF and BGP
>
>
> Don't you think that best way is to configure OSPF and BGP router ID
> statically so you know that this never comes up I think you
> can configure
> OSPF router id statically in IOS 12.1
>
> Just my 2 cents
>
> Iftikhar Khan
>
> -----Original Message-----
> From: Nathan Chessin [mailto:nchessin@cisco.com]
> Sent: Friday, November 08, 2002 1:15 PM
> To: 'ying c'; 'Conrad Bullock'; ccielab@groupstudy.com
> Subject: RE: OSPF and BGP
>
>
> I diagree with the statement. I am not wondering why they
> aren't installed,
> I am wondering why they aren't marked as valid. Just because
> there are
> already valid paths in the IGP doesn't mean BGP should be
> valid and best.
> That is what I was trying to figure out. Why isn't the BGP route
> synchronizing?
>
> Well, turns out the it was the BGP - OSPF router id issue.
> For *iBGP*, if a
> route is learned via OSPF, the OSPF router-id that the route
> was learned
> from has to match the iBGP peer BGP router-id for it to be
> marked as valid.
>
> You can image what a pain this would be if you have all your
> virtual links
> set up with router-ids in OSPF and then you have to change
> them to match the
> iBGP peer of a particular router. Or I guess you could change the BGP
> router-id, but still, could get ugly.
>
> Nate
>
> > -----Original Message-----
> > From: ying c [mailto:bf5tgh1@yahoo.com]
> > Sent: Friday, November 08, 2002 6:00 AM
> > To: Conrad Bullock; 'Nathan Chessin'; ccielab@groupstudy.com
> > Subject: RE: OSPF and BGP
> >
> >
> > I agree with your statement. There's one more problem
> > need to be fixed before BGP routes can be considered -
> > none of the routes in his BGP table were marked as
> > best path.
> >
> > Chang
> > --- Conrad Bullock <cjbullock@xtra.co.nz> wrote:
> > > Unless I'm missing the point, this looks like normal
> > > behaviour.
> > >
> > > iBGP has an administrative distance of 200.
> > >
> > > As the iBGP routes that you're talking about from
> > > iBGP are already in
> > > the routing table with an AD of less than 200, the
> > > iBGP routes are not
> > > installed.
> > >
> > > Conrad
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com
> > > [mailto:nobody@groupstudy.com] On Behalf Of
> > > Nathan Chessin
> > > Sent: Friday, 8 November 2002 9:10 p.m.
> > > To: ccielab@groupstudy.com
> > > Subject: OSPF and BGP
> > >
> > > Hi All,
> > >
> > > My routing and BGP tables look like the below.
> > > Question is, why isn't
> > > the
> > > BGP route being installed as valid. I have routes
> > > to next-hop and also
> > > the
> > > networks in the bgp table.
> > >
> > > I read that If the matching route is learned from an
> > > OSPF neighbor, its
> > > OSPF
> > > router ID must match the BGP router ID of the iBGP
> > > neighbor.
> > > I tried changing those and still no luck.
> > >
> > > Any ideas
> > >
> > > (AS 2) (AS 2)
> > > R3 ----iBGP---- R5
> > >
> > >
> > >
> > > R5 output below...
> > >
> > > Gateway of last resort is not set
> > >
> > > 34.0.0.0/24 is subnetted, 1 subnets
> > > O IA 34.1.1.0 [110/112] via 35.1.1.3, 00:00:22,
> > > Serial2/0
> > > 1.0.0.0/16 is subnetted, 1 subnets
> > > O E2 1.1.0.0 [110/50] via 35.1.1.3, 00:00:22,
> > > Serial2/0
> > > 35.0.0.0/24 is subnetted, 1 subnets
> > > C 35.1.1.0 is directly connected, Serial2/0
> > > O IA 2.0.0.0/8 [110/113] via 35.1.1.3, 00:00:22,
> > > Serial2/0
> > > 100.0.0.0/24 is subnetted, 1 subnets
> > > O E1 100.100.100.0 [110/132] via 35.1.1.3,
> > > 00:00:22, Serial2/0
> > > 3.0.0.0/32 is subnetted, 1 subnets
> > > O 3.3.3.3 [110/49] via 35.1.1.3, 00:00:23,
> > > Serial2/0
> > > 12.0.0.0/24 is subnetted, 1 subnets
> > > O 12.1.1.0 [110/112] via 35.1.1.3, 00:00:23,
> > > Serial2/0
> > > R5#sib
> > > BGP table version is 1, local router ID is
> > > 33.33.33.33
> > > Status codes: s suppressed, d damped, h history, *
> > > valid, > best, i -
> > > internal
> > > Origin codes: i - IGP, e - EGP, ? - incomplete
> > >
> > > Network Next Hop Metric
> > > LocPrf Weight Path
> > > * i1.1.0.0/16 12.1.1.1 23
> > > 100 0 1 ?
> > > * i100.100.100.0/24 12.1.1.1 23
> > > 100 0 1 ?
> > >
> > >
> > > Nate
> >
> >
> > __________________________________________________
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This archive was generated by hypermail 2.1.4 : Tue Dec 03 2002 - 07:22:55 GMT-3