From: soon ccie (soonccie@yahoo.com)
Date: Fri Feb 21 2003 - 06:31:30 GMT-3
How about redist the route from IGP to BGP at R3, then redist it back
IGP into BGP at R1? since redist routes takes precedence over eBGP
routes, R1 will source it.
HTH.
--- "Cameron, John" <johcamer@cisco.com> wrote:
> Actually Joe Martin raised a good point to me a bit ago - so
> I labed this up as follows:
>
> r3-----r1-----r2
>
> r3: AS10
> r1: AS30
> r2: AS20
>
> r3 peers only with r1
> r1 peers with r3 and r2
> r2 peers only with r3
>
> If I configure a loopback on r3 with the address 150.50.31.1/24 and
> add it
> to by BGP process it advertises as expected:
>
> r3#sib
> BGP table version is 70, local router ID is 204.100.100.33
> 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
> *> 150.50.31.0/24 0.0.0.0 0 32768 i
>
> r1#sib
> BGP table version is 15, local router ID is 204.100.100.1
> 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
> *> 150.50.31.0/24 204.100.100.2 0 0 10 i
>
> r2#sib
> BGP table version is 40, local router ID is 204.100.100.177
> 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
> *> 150.50.31.0/24 150.10.20.1 0 20 10 i
>
> Next I added "aggregate-address 150.50.31.0 255.255.255.0
> summary-only" to
> r1 BGP process and recieved the same output as before:
>
> router bgp 20
> bgp log-neighbor-changes
> aggregate-address 150.50.31.0 255.255.255.0 summary-only
> neighbor 150.10.20.2 remote-as 30
> neighbor 204.100.100.2 remote-as 10
>
> r3#sib
> BGP table version is 81, local router ID is 204.100.100.33
> 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
> *> 150.50.31.0/24 0.0.0.0 0 32768 i
>
>
> r1#sib
> BGP table version is 16, local router ID is 204.100.100.1
> 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
> *> 150.50.31.0/24 204.100.100.2 0 0 10 i
>
> r2#sib
> BGP table version is 46, local router ID is 204.100.100.177
> 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
> *> 150.50.31.0/24 150.10.20.1 0 20 10 i
>
> The only way I could get this to work is if I shortened the mask to
> /16 -
> which
> doesn't meet the requirments.
>
> on r1
>
> router bgp 20
> bgp log-neighbor-changes
> aggregate-address 150.50.0.0 255.255.0.0 summary-only
> neighbor 150.10.20.2 remote-as 30
> neighbor 204.100.100.2 remote-as 10
>
>
> r1#sib
> BGP table version is 18, local router ID is 204.100.100.1
> 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
> *> 150.50.0.0 0.0.0.0 32768 i
> s> 150.50.31.0/24 204.100.100.2 0 0 10 i
>
>
> r2#sib
> BGP table version is 48, local router ID is 204.100.100.177
> 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
> *> 150.50.0.0 150.10.20.1 0 20 i
>
>
> So I retract what I said before ;-(
>
> Sorry for the confusion
> JDC
>
>
> -----Original Message-----
> From: Peter van Oene [mailto:pvo@usermail.com]
> Sent: Tuesday, February 18, 2003 12:54 PM
> To: ccielab@groupstudy.com
> Subject: RE: GBP Question
>
>
> At 09:22 AM 2/18/2003 -0500, Cameron, John wrote:
> >Use the following on Router B:
> >
> >aggregate-address 150.50.31.0 255.255.255.0 summary-only
>
> For what its worth, this is an entirely different route than the
> original
> path. Why not just filter the incoming route and announce your own
> if we
> are taking that much liberty? Of note, I'm not entirely sure that
> the
> aggregate-address command will accept a prefix of the same depth for
> a
> contributor. Indeed, if it did, this would seem broken to me.
>
> >This will remove Router A as the originator of the prefix
> >an make it "look" as if Router C ownes the prefix.
>
> This will create two routes in the network where one previously
> existed. In my books, this wouldn't be a valid answer to the
> question,
> then again I expect I wouldn't ask for BGP to be broken in the
> question.
>
> Pete
>
>
> >HTH,
> >JDC
> >
> >
> >-----Original Message-----
> >From: love cisco [mailto:love_cisco@hotmail.com]
> >Sent: Tuesday, February 18, 2003 5:07 AM
> >To: ccielab@groupstudy.com
> >Subject: GBP Question
> >
> >
> >I have a question about filtering BGP As number in AS path table.
> >
> >Router A has a ip address 150.50.31.1/24 distributed in bgp AS100.
> In
> >Router C bgp table, you will see the 150.50.31.0 network as-path is
> "200
> >100". My question is how to config bgp in router B to filtering as
> path
> >number 100. So router C will
> >only 150.50.31.0 network as-path is "200"?
> >
> > ------------ ------------ ------------
> > | Router A |------------| Router B |--------------| Router C |
> > | AS 100 | | AS 200 | | AS 300 |
> > ------------ ------------ ------------
> > 150.50.31.1/24
> >
> >_________________________________________________________________
> >OmSCJ@=gIOWn4s5D5gWSSJ<~O5M3!* MSN Hotmail!# http://www.hotmail.com
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2003 - 11:06:30 GMT-3