H3C Technologies H3C S10500 Series Switches - Manual (Page 365)

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*Nov 5 11:42:24:187 2009 SwitchC RM/6/RMDEBUG: BGP_BFD: Reset BGP session 3000::1 for
BFD session down.
*Nov 5 11:42:24:187 2009 SwitchC RM/6/RMDEBUG: BGP_BFD: Send DELETE msg to BFD, Connection
type DIRECT, Src IP 3001::3, Dst IP 3000::1, Instance ID 0.
# Display route 1200::0/64 on Switch C, and you can see that Switch A and Switch C communicate
through Switch D.
<SwitchC> display ipv6 routing-table 1200::0 64 verbose
Routing Table :
Summary Count : 1
Destination : 1200:: PrefixLength : 64
NextHop : 2000::1 Preference : 255
RelayNextHop : 2001::2 Tag : 0H
Neighbor : 2000::1 ProcessID : 0
Interface : Vlan-interface201 Protocol : BGP4+
State : Active Adv Cost : 100
Tunnel ID : 0x0 Label : NULL
Age : 4635sec
The output shows that Switch C has one route to reach network 1200::0/64, that is, Switch C<—>Switch
D<—>Switch A.
Troubleshooting IPv6 BGP configuration
IPv6 BGP peer relationship not established
Symptom
Display BGP peer information by using the display bgp ipv6 peer command. The state of the connection
to the peer cannot become established.
Analysis
To become IPv6 BGP peers, any two routers must establish a TCP session using port 179 and exchange
open messages successfully.
Processing steps
1. Use the display current-configuration command to check that the peer’s AS number is correct.
2. Use the display bgp ipv6 peer command to check that the peer’s IPv6 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 not directly connected, check that the peer ebgp-max-hop command is configured.
5. Check that a valid route to the peer is available.
6. Use the ping command to check the connectivity to the peer.
7. Use the display tcp ipv6 status command to check the TCP connection.
8. Check whether an ACL for disabling TCP port 179 is configured.