I have a question about Next-Hop-Self I've done almost all Labs (Vols II & III)and I noticed that in about 50% of the time (perhaps more)when a Router has both, EBGP and IBGP neighborsNext-Hop-Self is configured on the peering with the IBGP neighbors It is quite clear to me why this is necessary.So that's not the question. What is not so clear why this is not done in ALL cases (100% of the time) I mean, would it hurt to configure Next-Hop-Self on a Router with IBGP neighborsof course ONLY if this same Router also has an EBGP neighbor from which is receiving some routes? Frankly I do not see how this could be badand if I make this a "rule", I think that I would be avoiding potential problems. Are there are any potential problems with this approach?
--- On Tue, 12/21/10, Nilesh Mehta <[email protected]> wrote: From: Nilesh Mehta <[email protected]> Subject: Re: [OSL | CCIE_RS] VOL1 LAB14 BGP route-reflector & next-hop-self To: "Huang, Kevin" <[email protected]> Cc: "[email protected]" <[email protected]> Date: Tuesday, December 21, 2010, 12:50 PM next hop self command does not work when you have IBGP Route reflector and client and next hop doesn't change, but it does work when route reflector has EBGP connection. Thanks Nilesh On Tue, Dec 21, 2010 at 4:58 AM, Huang, Kevin <[email protected]> wrote: > 14.1 route-reflector & next-hop-self > > When I initially configured R2 as route reflector & next-hop-self like how > DSG describes, the next-hop-self part wasn't working. > router bgp 1 > ... > address-family ipv4 > neighbor IBGP next-hop-self > > When R5 received the reflected routes from R1, they all had R1's loopback > as next hop instead of R2's. > I had to use a route-map to manually set the next hop as the "peer address" > to make it work: > route-map NEXT-HOP permit 10 > set ip next-hop peer-address > > router bgp 1 > ... > address-family ipv4 > neighbor IBGP route-reflector-client > neighbor IBGP route-map NEXT-HOP out > > A cisco.com document says: > "Do not use the neighbor next-hop-self command to modify the next hop > attribute for a route reflector when this feature is enabled for a route > reflector client." > > > http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fs_bgpnh.html#wp1027202 > > Could someone please confirm if the solution to use next-hop-self on the > route-reflector was an error on the DSG? > > Thanks, > Kevin > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
