Re: path exists in BGP table, but no route in IP Routing table
Best guess given info given:- R4 does not have an IP route to the BGP advertised NEXT-HOP address for R1. If you do a "show ip bgp" on R4, the R1 route should show up as invalid. ""Sean Wu"" [EMAIL PROTECTED] wrote in message 8rgfm3$ce4$[EMAIL PROTECTED]">news:8rgfm3$ce4$[EMAIL PROTECTED]... So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths Any idea? Thanks, Sean **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: path exists in BGP table, but no route in IP Routing table
Umm - sorry, it should be... "show ip bgp w.x.y.z" will indicate the next hop is (inaccessible). Regards, Adrian ""Adrian Chew"" [EMAIL PROTECTED] wrote in message 8rjji6$e79$[EMAIL PROTECTED]">news:8rjji6$e79$[EMAIL PROTECTED]... Best guess given info given:- R4 does not have an IP route to the BGP advertised NEXT-HOP address for R1. If you do a "show ip bgp" on R4, the R1 route should show up as invalid. ""Sean Wu"" [EMAIL PROTECTED] wrote in message 8rgfm3$ce4$[EMAIL PROTECTED]">news:8rgfm3$ce4$[EMAIL PROTECTED]... So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths Any idea? Thanks, Sean **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: path exists in BGP table, but no route in IP Routing table
On Wed, 4 Oct 2000, Sean Wu wrote: So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths How are you injecting IP into BGP? Network statements? Redistribution from IGP? Can you post configs? -- Jay Hennigan - Network Administration - [EMAIL PROTECTED] NetLojix Communications, Inc. NASDAQ: NETX - http://www.netlojix.com/ WestNet: Connecting you to the planet. 805 884-6323 **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: path exists in BGP table, but no route in IP Routing table
usually this means that R4 does not have a way to reach the "next-hop" for the R1 route. If you look at the R1 route in the BGP table, you will see a BGP "next-hop" for this route. If that "next-hop" is not reachable (via a directly connected interface for example), then the route will NOT go into your IGP..but at the same time it will sit fine in your BGP. set "next-hop-self" on routers to avoid stuff like this. R4 you see, has no means to get to R1 directly. When the R1 route is learned by R3, the next-hop shows "R1". Then when the route is passed via iBGP to R4the next hop information is preserved..as R1and since R4 doesn't know how to get to R1...your screwed :) next-hop-self in the neighbor statments on R3. Brian On Wed, 4 Oct 2000, Sean Wu wrote: So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths Any idea? Thanks, Sean **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- Brian Feeny, CCNP, CCDA [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: path exists in BGP table, but no route in IP Routing table
Sean, I would assume that R3 also has two BGP routes to R2, but does not have an entry in the routing table either. Step 1 of the BGP decision process is to ignore routes with an inaccessible next hop. Make sure that R4 knows how to reach the interface(s) advertising the networks that R1 is advertising. Normally, this would be done with an IGP such as OSPF, RIP, IGRP, etc; it could be done with static routes, but this is not a scalable solution. --phil On Wed, 4 Oct 2000, Sean Wu wrote: So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
path exists in BGP table, but no route in IP Routing table
So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths Any idea? Thanks, Sean **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: path exists in BGP table, but no route in IP Routing table
try 'no sync' in your BGP config. A show IP bgp would help too. Might try 'next-hop-self' on neighbor statement to R4. ""Sean Wu"" [EMAIL PROTECTED] wrote in message 8rgfm3$ce4$[EMAIL PROTECTED]">news:8rgfm3$ce4$[EMAIL PROTECTED]... So what possible reason can cause this problem? I have four routers, R1 --- R2 ^ ^ | | | | | | v v R3 --- R4 AS1: R1 AS2: R2 AS3: R3+R4 IBGP between R3 and R4, EBGP between R1/R2, R2/R4, R1/R3 Everything else looks fine, and almost symetric configuration on R1/R3 and R2/R4 But R3 can see R2 in routing table and BGP table, while R4 doesn't see R1's ip in ip routing table, but it does see R1 in BGP table via two different paths Any idea? Thanks, Sean **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
