From: steven.j.nelson@xxxxxx
Date: Thu Jun 06 2002 - 06:44:30 GMT-3
Nick,
The best advice I can give without NDA Violation is to learn these little
tricks inside out. I first saw this when I read Pete Van Oene's posts on
the subject and decided to look into it. I found that the best way round
this sort of thing was confederations, but I also had a few scenarios where
confeds were not available and therefore had to use another igp.
There are some excellent posts on this subject in the group, if you cannot
find them mail me offline and I'll send them on through for you.
But have a play with this ospf RID thing combined with route reflectors,
it's fun to say the least.
Thanks and HTH
Steve
-----Original Message-----
From: Nick Shah [mailto:nshah@connect.com.au]
Sent: 06 June 2002 10:26
To: Nelson,SJ,Steven,IVNH33 C; p_chopin; Eddy.Fong
Cc: ccielab
Subject: Re: (Solved)
Steven,
what other probs (apart from manipulating router ids) can we come across in
a scenario like this. pl. explain.
ps. This is one hell of a scenario, and network admins. will maul us if we
do something like this in a prod netw :)
rgds
Nick
-----Original Message-----
From: steven.j.nelson@bt.com <steven.j.nelson@bt.com>
To: nshah@connect.com.au <nshah@connect.com.au>; p_chopin@yahoo.com
<p_chopin@yahoo.com>; Eddy.Fong@hp.com <Eddy.Fong@hp.com>
Cc: ccielab@groupstudy.com <ccielab@groupstudy.com>
Date: Thursday, 6 June 2002 7:07
Subject: RE: (Solved)
>Nick,
>
>Yep, correct
>
>There are some problems that appear when using this with route reflectors,
>you may want to look into that.
>
>Thanks
>
>Steve
>
>-----Original Message-----
>From: Nick Shah [mailto:nshah@connect.com.au]
>Sent: 06 June 2002 10:17
>To: Nelson,SJ,Steven,IVNH33 C; p_chopin; Eddy.Fong
>Cc: ccielab
>Subject: Re: (Solved)
>
>
>Paul,
>
>I have managed to get this one working.... I am posting the relevant
configs
>as under
>
>R1 # doesnt have anything running except RIP...
>
>
> 3.0.0.0/32 is subnetted, 1 subnets
>C 3.3.3.3 is directly connected, Loopback0
>C 200.100.100.0/24 is directly connected, Serial0
> 199.199.2.0/30 is subnetted, 1 subnets
>C 199.199.2.4 is directly connected, Serial1
> 199.199.1.0/30 is subnetted, 1 subnets
>C 199.199.1.0 is directly connected, Ethernet0
>
>R2 #
>
>
>
>router ospf 1
>router-id 5.5.5.5 (keep this router id in mind, check below)
> redistribute rip metric 20 subnets (redistributing RIP routes from R1)
> network 199.199.1.1 0.0.0.0 area 0
> network 199.199.2.1 0.0.0.0 area 0
> network 199.199.3.1 0.0.0.0 area 0
>!
>router rip
> network 199.199.1.0
>!
>router bgp 2
> bgp router-id 9.9.9.9 (note this will is purposely different from the OSPF
>router id)
> neighbor 199.199.1.2 remote-as 1
> neighbor 199.199.3.2 remote-as 3
> no auto-summary
>
>
>R3 #
>
>router ospf 1
>router-id 4.4.4.4
> log-adjacency-changes
> network 199.199.3.2 0.0.0.0 area 0
>!
>router bgp 3
> bgp router-id 5.5.5.5 (note that this router id is same as ospf router id
>on R2)
> bgp cluster-id 67372036
> bgp log-neighbor-changes
> neighbor 199.199.2.2 remote-as 3
> neighbor 199.199.3.1 remote-as 2
>
>
>R4 #
>
>R4#sh ip bg
>BGP table version is 2, local router ID is 2.2.2.2
>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
>*>i200.100.100.0 199.199.3.1 100 0 2 1 i
>RouterB#sh ip bgp 200.100.100.0
>BGP routing table entry for 200.100.100.0/24, version 2
>Paths: (1 available, best #1, table Default-IP-Routing-Table)
> Advertised to non peer-group peers:
> 199.199.4.2
> 2 1, (Received from a RR-client)
> 199.199.3.1 (metric 75) from 199.199.3.2 (5.5.5.5)
> Origin IGP, localpref 100, valid, internal, synchronized, best
>R4#
>
>Now, I will also try to lab it up with Confeds and acheive the same result,
>then without using OSPF (as steve suggested, using EIGRP or RIP)
>
>rgds
>Nick
>-----Original Message-----
>From: steven.j.nelson@bt.com <steven.j.nelson@bt.com>
>To: p_chopin@yahoo.com <p_chopin@yahoo.com>; Eddy.Fong@hp.com
><Eddy.Fong@hp.com>
>Cc: ccielab@groupstudy.com <ccielab@groupstudy.com>
>Date: Thursday, 6 June 2002 5:56
>Subject: RE:
>
>
>>Guys
>>
>>Eddy is right, the problem is that the igp route from R2 is via ibgp and
>the
>>igp route is from R3 so BGP says these routes are from different sources
>and
>>therefore are "untrustworthy" so hence not synchronised.
>>
>>Confeds will work fine but you need to learn this one with and without
>them.
>>maybe use an igp that does not depend on RIDs such as eigrp etc etc.
>>
>>Have a play with it and know it back to front you'll need it.
>>
>>HTH
>>
>>Steve
>>
>>-----Original Message-----
>>From: Paul [mailto:p_chopin@yahoo.com]
>>Sent: 06 June 2002 06:24
>>To: Fong, Eddy
>>Cc: ccielab@groupstudy.com
>>Subject: RE:
>>
>>
>>Is there any remedy except confederations?
>>Paul
>>--- "Fong, Eddy" <Eddy.Fong@hp.com> wrote:
>>> I think we have come across this issue before.
>>> Anyway, it's because the IGP route 200.100.100.0/24
>>> is from R2. But the iBGP route is from R3. When you
>>> have OSPF as IGP and want to syn with BGP, the route
>>> originator R-Ids have to be the same. Otherwaise
>>> it's not synchronized and, hence, not advertise to
>>> R5.
>>>
>>>
>>> -----Original Message-----
>>> From: Paul [mailto:p_chopin@yahoo.com]
>>> Sent: Thursday, June 06, 2002 10:59 AM
>>> To: ccielab@groupstudy.com
>>> Subject:
>>>
>>>
>>> Hi group,
>>> I just run into another interesting little problem.
>>> I have R1-R2---R3
>>> | |
>>> \ /
>>> R4---R5
>>> R1 is running RiP. R2,R3,R4,R5 are running ospf. R2
>>> is
>>> redistributing rip into ospf domain.R1 is inserting
>>> route 200.100.100.0/24 to BGP through network
>>> statement and Redistributing this route into Rip as
>>> well. R1 is in AS1 , R2 in AS3, and R5,R4,R5 in As
>>> 3.EBGP sessions R1-R2, R2-R3. IBGP sesions R3-R4,
>>> R4-R5. R4 is route reflector.Synch is enable on all
>>> the routers.Question is why on R4 BGP table says,
>>> that
>>> route 200.100.100.0/24 is not synchronized even it's
>>> known through ospf and is not being pushed to R5.
>>> All routers have hard coded identical routers id in
>>> ospf and BGP.
>>> I've been struggling almost a week with this one.I
>>> searched and read white papers on CCO - I still
>>> don't
>>> understand.I'm missing really something important.
>>> Can you help?
>>> Paul
>>>
>>>
>>>
>>>
>>>
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