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RE: No Best Path with BGP posted 12/02/2005
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Is 150.1.5.5 in the routing table?

More importantly, is it in there with something other than a default route
to get to it?

Seems the router is telling you the problem.  :)  But of course, right at
the end of time doesn't exactly help in testing things, does it!

Scott 

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of
Anthony Sequeira
Sent: Friday, December 02, 2005 8:42 PM
To: Cisco certification
Subject: No Best Path with BGP

Wow - is this interesting....sadly it happened right as I got kicked off my
rental rack today....so I need the expertise of the group to help me
understand.....

Simple BGP topology......

R5(AS 200) -------------R2(AS 300)

I wanted to use a route-map to change the next-hop value of incoming routes
from R5 so that the next hop will be the loopback of R5. By the way - I had
best paths and everything was fine before trying this change....

R2#
!
router bgp 300
 no synchronization
 neighbor 136.1.245.5 remote-as 200
 neighbor 136.1.245.5 route-map HOPPER in  no auto-summary !
route-map HOPPER permit 10
 set ip next-hop 150.1.5.5

After this config - the next hop does change - but now no BEST PATHs:

R2#show ip bgp
BGP table version is 7, local router ID is 150.1.2.2 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
*  205.90.31.0      150.1.5.5                              0 200 254 ?
*  220.20.3.0       150.1.5.5                              0 200 254 ?
*  222.22.2.0       150.1.5.5                              0 200 254 ?
I try and get some details:

R2#show ip bgp 222.22.2.0
BGP routing table entry for 222.22.2.0/24, version 7
Paths: (1 available, no best path)
  Not advertised to any peer
  200 254
    150.1.5.5 (inaccessible) from 136.1.245.5 (150.1.5.5)
      Origin incomplete, localpref 100, valid, external

OK - so 150.1.5.5 is inaccessible from 136.1.245.5? My goodness - these
interfaces are on the same router! What gives? Could it be that
136.1.245.5is a Frame Relay interface that is not pingable from the loopback
address ( 150.1.5.5)? OK - I know I am reaching - but I am tired after 10
hours on the rack.....

Can anyone help?

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