H3C Technologies H3C SecPath F1000-E - Manual (Page 524)

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*Nov 5 11:42:24:187 2009 RouterC RM/6/RMDEBUG: BGP_BFD: Reset BGP session 3.0.1.1
for BFD session down.
*Nov 5 11:42:24:187 2009 RouterC RM/6/RMDEBUG: BGP_BFD: Send DELETE msg to BFD,
Connection type DIRECT, Src IP 3.0.2.2, Dst IP 3.0.1.1, Instance ID 0.
# Display route 1.1.1.0/24 on Router C, and you can see that SecPath A and Router C
communicate through Router D.
<RouterC> display ip routing-table 1.1.1.0 24 verbose
Routing Table : Public
Summary Count : 1
Destination: 1.1.1.0/24
Protocol: BGP Process ID: 0
Preference: 0 Cost: 100
NextHop: 2.0.1.1 Interface: GigabitEthernet0/2
BkNextHop: 0.0.0.0 BkInterface:
RelyNextHop: 2.0.2.1 Neighbor : 2.0.1.1
Tunnel ID: 0x0 Label: NULL
State: Active Adv Age: 00h09m54s
Tag: 0
The output shows that Router C has one route to reach network 1.1.1.0/24, that is, Router C<
—
>Router D<—>SecPath A.
Troubleshooting BGP
BGP peer relationship not established
Symptom
Display BGP peer information by using the display bgp peer command. The state of the connection to a
peer cannot become established.
Analysis
To become BGP peers, any two routers need to establish a TCP session using port 179 and exchange
Open messages successfully.
Solution
1. Use the display current-configuration command to check that the peer's AS number is correct.
2. Use the display bgp peer command to check that the peer's IP address is correct.
3. If a loopback interface is used, check that the loopback interface is specified with the peer
connect-interface command.
4. If the peer is a non-direct EBGP peer, check that the peer ebgp-max-hop command is configured.
5. If the peer ttl-security hops command is configured, check that the command is configured on the
peer, and the hop-count values configured on them are greater than the number of hops between
them.
6. Check that a valid route to the peer is available.
7. Use the ping command to check the connectivity to the peer.
8. Use the display tcp status command to check the TCP connection.