Removing AS101 from the path of routes advertised to R2's is a job for * replace-as *keyword.
What *no-prepend* keyword will do in your config is to remove your local-as (100) that R1 would otherwise prepend to adverts received from R2 before sending them out. You will not see AS 100 in the path of adverts R1 makes to R3(3.3.3.3). Check on R3 whether local-as worked, not on R1. On 24 February 2012 12:48, Bodnar, Edward <[email protected]> wrote: > Let me know if you see anything off on the config. Still not sure why > this is not working. I was expecting to see R2 not having AS 101 in it’s > path. **** > > ** ** > > ** ** > > R1**** > > ** ** > > router bgp 101**** > > no synchronization**** > > bgp router-id 1.1.1.1**** > > bgp log-neighbor-changes**** > > network 33.33.33.0 mask 255.255.255.0**** > > network 55.55.55.0 mask 255.255.255.0**** > > network 55.55.56.0 mask 255.255.255.0**** > > network 55.55.57.0 mask 255.255.255.0**** > > network 55.55.58.0 mask 255.255.255.0**** > > network 55.55.59.0 mask 255.255.255.0**** > > network 100.100.10.0 mask 255.255.255.0**** > > aggregate-address 55.55.0.0 255.255.192.0 summary-only**** > > neighbor 2.2.2.2 remote-as 200**** > > neighbor 2.2.2.2 local-as 100 no-prepend**** > > neighbor 2.2.2.2 ebgp-multihop 255**** > > neighbor 2.2.2.2 update-source Loopback0**** > > neighbor 2.2.2.2 send-community**** > > neighbor 2.2.2.2 route-map CoM out**** > > neighbor 3.3.3.3 remote-as 300**** > > neighbor 3.3.3.3 local-as 100 no-prepend**** > > neighbor 3.3.3.3 ebgp-multihop 255**** > > neighbor 3.3.3.3 update-source Loopback0**** > > ** ** > > ** ** > > R2**** > > ** ** > > router bgp 200**** > > no synchronization**** > > bgp log-neighbor-changes**** > > bgp inject-map NEW exist-map NEED-UM**** > > neighbor 1.1.1.1 remote-as 100**** > > neighbor 1.1.1.1 ebgp-multihop 255**** > > neighbor 1.1.1.1 update-source Loopback0**** > > neighbor 5.5.5.5 remote-as 200**** > > neighbor 5.5.5.5 update-source Loopback0**** > > neighbor 5.5.5.5 send-community**** > > neighbor 5.5.5.5 default-originate**** > > no auto-summary**** > > ** ** > > ** ** > > ** ** > > R2#sh ip bgp**** > > BGP table version is 65, local router ID is 2.2.2.2**** > > Status codes: s suppressed, d damped, h history, * valid, > best, i - > internal,**** > > r RIB-failure, S Stale**** > > Origin codes: i - IGP, e - EGP, ? - incomplete**** > > ** ** > > Network Next Hop Metric LocPrf Weight Path**** > > *> 33.33.33.0/24 1.1.1.1 0 0 100 *101* i** > ** > > *> 55.55.0.0/18 1.1.1.1 0 0 100 *101* i** > ** > > *> 55.55.56.0/24 1.1.1.1 0 ?**** > > *> 100.100.10.0/24 1.1.1.1 0 0 100 *101* i** > ** > > ** ** > > ** ** > > ** ** > > ** ** > > *From:* [email protected] [mailto:[email protected]] *On Behalf > Of *Oluwagbenga Oyebande > *Sent:* Thursday, February 23, 2012 10:12 PM > *To:* ar > *Cc:* Bodnar, Edward; Steve Storniak; [email protected]; > [email protected] > > *Subject:* Re: [OSL | CCIE_RS] BGP local-as no-pepend**** > > ** ** > > It actually works as Adams has proved. The problem is that people wrongly > expect it to work on adverts to the local-as peer. It works on adverts to > other bgp peers. It strips off the local-as that was prepended to routes > received from the local-as peer.**** > > ** ** > > ** ** > > On 24 February 2012 02:53, ar <[email protected]> wrote:**** > > Hi. > > This local-as no prepend feature is not working based on my experience. > What platforms are you using?**** > > > > > > > ________________________________ > From: "Bodnar, Edward" <[email protected]>**** > > To: Steve Storniak <[email protected]>; "[email protected]" < > [email protected]> > Cc: "[email protected]" <[email protected]> > Sent: Thursday, February 23, 2012 4:51 PM**** > > Subject: Re: [OSL | CCIE_RS] BGP local-as no-pepend > > I will grab and post my config tomorrow. Either I am not understanding > this command or I am not configuring it right. It’s a fairly simple > command so I can’t see the latter but I will post my config. > > From: Steve Storniak [mailto:[email protected]] > Sent: Thursday, February 23, 2012 7:15 PM > To: [email protected]; Bodnar, Edward > Cc: [email protected] > Subject: Re: [OSL | CCIE_RS] BGP local-as no-pepend > > > Per RFC "no-prepend" instructs the node to not add the local as to > prefixes received from other eBGP peers. > "Replace-as" removes the local as in the as-path sent to eBGP peers. > Am O wrong? > > Steve > > > ________________________________ > From: Bodnar, Edward <[email protected]>; > To: Adam Booth <[email protected]>; > Cc: [email protected] <[email protected]>; > Subject: Re: [OSL | CCIE_RS] BGP local-as no-pepend > Sent: Thu, Feb 23, 2012 11:27:59 PM > I 100% agree. Just not sure what the local-as no-prepend does. > > From: Adam Booth [mailto:[email protected]<javascript:return>] > Sent: Thursday, February 23, 2012 6:11 PM > To: Bodnar, Edward > Cc: [email protected]<javascript:return> > Subject: Re: [OSL | CCIE_RS] BGP local-as no-pepend > > Hi Edward. > > If also you include "replace-as" in the neighbor statement, AS 100 should > be hidden. > > Cheers, > Adam > > On Fri, Feb 24, 2012 at 6:48 AM, Bodnar, Edward <[email protected] > <javascript:return><mailto:[email protected]<javascript:return>>> > wrote: > Not sure what this command is suppose to do . > > I set it and it does not filter any AS's > > > Router bgp 100 > Neigh 2.2.2.2 Local-as 10 no-prepend > > The router on the other side will still see AS 100 and AS10 in its path. > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com<http://www.ipexpert.com> > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com<http://www.PlatinumPlacement.com> > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs**** > > > > **** > > ** ** > > -- > -- > Olugbenga Oyebande > MD, DAIT > 234-803-302-5287 **** > > http://www.dait-ng.com > Cisco Networks, Network Security & Quality of Service > DAIT Linux Enterprise Network Servers, Web Portal Projects**** > > Broadband Internet Deployment & ISP Consultancy**** > > ** ** > -- -- Olugbenga Oyebande MD, DAIT 234-803-302-5287 http://www.dait-ng.com Cisco Networks, Network Security & Quality of Service DAIT Linux Enterprise Network Servers, Web Portal Projects Broadband Internet Deployment & ISP Consultancy _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
