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Troubleshooting
Router# show ip bgp neighbors 192.168.0.25 routes
BGP local router ID is 192.168.88.1, local AS is 501.
Status codes: * valid, > best, i - internal, o - local
Origin codes: i - IGP, e - EGP, ? - incomplete
Network NextHop Metric LocPrf Path
*> 192.168.5.0/24 192.168.0.25 500 i
Total RIB entries = 2
Router# show ip bgp neighbors 192.168.0.25 received-routes
BGP local router ID is 192.168.88.1, local AS is 501.
Status codes: * valid, > best, i - internal, o - local
Origin codes: i - IGP, e - EGP, ? - incomplete
Network NextHop Metric LocPrf Path
*> 192.168.5.0/24 192.168.0.25 500 i
192.168.77.0/24 192.168.0.25 500 502 i
Total RIB entries = 2
No * indicates that the
AOS device considers
the route invalid.
The router is filtering
out the route to
192.168.77.0 /24.
The AOS device is
accepting one route
from the neighbor.
Figure 11. Comparing Accepted Routes to All Routes Received
The next step in troubleshooting an interface that will not accept routes is to remove filters from the
neighbor (refer to Removing Filters on page 75). If the filter is the problem, then troubleshoot it as
described in Troubleshooting a Prefix List on page 79 and Troubleshooting a Route Map on page 80.
BGP Cannot Communicate with a Neighbor
Unlike other routing protocols, BGP does not automatically search for and exchange routes with connected
routers. Each BGP neighbor must be manually added and configured on the AOS device.
First, view the BGP neighbor and double-check its IPv4 address:
#show ip bgp neighbors
Ping the neighbor and check connectivity.
If the ping is successful, but the AOS device does not seem to be exchanging BGP messages, the
maximum hop count for BGP messages might need to be adjusted using the ebgp-multihop command.
Typically, external neighbors can be reached from a directly connected interface making them one hop
away. If they are not, then the number of hops between the interface and the neighbor must be specified.
For example:
#ebgp-mulithop 4
A loopback interface adds a hop to the route. Even if the external neighbor is directly
connected, ebgp-multihop must be enabled if a loopback interface is used as the source
BGP interface. Refer to eBGP Multihop on page 17 for additional information on this
command.
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