From: William Lijewski (ccie8642@hotmail.com)
Date: Tue Jul 22 2003 - 02:08:30 GMT-3
It all has to do with where the route gets into OSPF. It needs to be put
into OSPF on R5 so that R5 is seen as the OSPF Origin for that route. No
other way to do it...
Bill Lijewski
CCIE #8642
>From: Peng Zheng <zpnist@yahoo.com>
>Reply-To: Peng Zheng <zpnist@yahoo.com>
>To: Jonathan V Hays <jhays@jtan.com>
>CC: ccielab@groupstudy.com
>Subject: RE: route not synchronized
>Date: Mon, 21 Jul 2003 19:05:42 -0700 (PDT)
>
>If it's possible if I do not put 62.9.1.0 into BGP on
>R6? Instead, I redistribute OSPF into BGP on R5.
>
>--- Jonathan V Hays <jhays@jtan.com> wrote:
> > Interesting scenario.
> >
> > Since you don't post your configs (why not?), we
> > have to guess at what
> > exactly you are doing. Let me guess that you are
> > redistributing
> > 62.9.1.0/24 into OSPF on R6 and also injecting
> > 62.9.1.0/24 into BGP with
> > the network command, which is what I did when I
> > attempted to recreate
> > your scenario:
> >
> > I used the same areas and created a virtual link to
> > area 2, as you
> > described. However, initially I did not redistribute
> > anything except
> > redistributing a loopback on R6, with the address
> > 62.9.1.6/24, into
> > OSPF.
> >
> > Here's my network:
> >
> > R6-e0--192.68.56.0--e0-R5-e1--192.168.1.0--e0-R13
> >
> > Initially the 62.9.1.0/24 route appeared in BGP
> > tables on all three
> > routers as follows:
> >
> > r6_tsrv#b
> > BGP table version is 2, local router ID is 129.6.6.6
> > 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
> > *> 62.9.1.0/24 0.0.0.0 0
> > 32768 i
> > r6_tsrv#
> > ==========r5#b
> > BGP table version is 2, local router ID is 129.5.5.5
> > 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
> > *> 62.9.1.0/24 192.168.56.6 0
> > 0 10 i
> > ==========
> > r13#b
> > BGP table version is 1, local router ID is
> > 129.13.13.13
> > 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
> > * i62.9.1.0/24 192.168.56.6 0
> > 100 0 10 i
> > ==========
> > Since it's not a best route, it won't go into the
> > routing table on r13.
> > As you point out, that's because BGP says the route
> > orginates from R5
> > and OSPF says it originates from R6.
> >
> > BGP - from 192.168.1.5 (129.5.5.5)
> > RT - from 129.6.6.6
> >
> > Here is the detailed output of what I had:
> >
> > 13#b 62.9.1.0
> > BGP routing table entry for 62.9.1.0/24, version 0
> > Paths: (1 available, no best path)
> > Not advertised to any peer
> > 10
> > 192.168.56.6 (metric 20) from 192.168.1.5
> > (129.5.5.5)
> > Origin IGP, metric 0, localpref 100, valid,
> > internal, not
> > synchronized
> > r13#i 62.9.1.0
> > Routing entry for 62.9.1.0/24
> > Known via "ospf 1", distance 110, metric 20, type
> > extern 2, forward
> > metric 20
> > Last update from 192.168.1.5 on Ethernet0,
> > 01:19:32 ago
> > Routing Descriptor Blocks:
> > * 192.168.1.5, from 129.6.6.6, 01:19:32 ago, via
> > Ethernet0
> > Route metric is 20, traffic share count is 1
> >
> > If you do what Bill suggested and redistribute the
> > BGP route 62.9.1.0/24
> > into OSPF on r5, then OSPF on r13 will now say that
> > the route originates
> > from R5 and will put it into the routing table.
> >
> > R5:
> > router ospf 1
> > redistribute bgp 20 metric 20 subnets
> >
> >
> > r13#b 62.9.1.0
> > BGP routing table entry for 62.9.1.0/24, version 2
> > Paths: (1 available, best #1, table
> > Default-IP-Routing-Table)
> > Not advertised to any peer
> > 10
> > 192.168.56.6 (metric 20) from 192.168.1.5
> > (129.5.5.5)
> > Origin IGP, metric 0, localpref 100, valid,
> > internal,
> > synchronized, best
> > r13#i 62.9.1.0
> > Routing entry for 62.9.1.0/24
> > Known via "ospf 1", distance 110, metric 20
> > Tag 10, type extern 2, forward metric 10
> > Last update from 192.168.1.5 on Ethernet0,
> > 00:01:33 ago
> > Routing Descriptor Blocks:
> > * 192.168.1.5, from 129.5.5.5, 00:01:33 ago, via
> > Ethernet0
> > Route metric is 20, traffic share count is 1
> > ------------
> > In summary:
> >
> > before redistribution on r13:
> > BGP - from 192.168.1.5 (129.5.5.5)
> > RT - from 129.6.6.6
> >
> > after redistribution on r13:
> > BGP - from 192.168.1.5 (129.5.5.5)
> > RT - from 129.5.5.5 <==
> >
> > HTH,
> >
> > Jonathan
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com] On Behalf Of
> > Peng Zheng
> > Sent: Monday, July 21, 2003 12:55 PM
> > To: William Lijewski
> > Cc: ccielab@groupstudy.com
> > Subject: Re: route not synchronized
> >
> >
> > But that route is directly connected to r6. I can
> > only redistributing it from r6.
> >
> >
> > --- William Lijewski <ccie8642@hotmail.com> wrote:
> > > Is there some reason why you are redistributing
> > the
> > > route into OSPF on R6?
> > > The router that you redistribute the BGP into the
> > > OSPF will be the origin
> > > for the OSPF. If you redistribute on R5 then R5
> > > will show as the origin of
> > > the route for OSPF, and your BGP and OSPF router
> > IDs
> > > will match up on R13.
> > >
> > > Bill Lijewski
> > > CCIE #8642
> > >
> >
> >
>
>
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