H3C Technologies H3C SR8800 - Manual (Page 399)

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Age : 4538sec
Destination : 1200:: PrefixLength : 64
NextHop : 2001::1 Preference : 255
IpPrecedence : QosLcId :
RelayNextHop : FE80::223:89FF:FEEF:9A04 Tag : 0H
Neighbor : 2001::1 ProcessID : 0
Interface : GigabitEthernet3/1/2 Protocol : BGP4+
State : Inactive Adv GotQ Cost : 100
Tunnel ID : 0x0 Label : NULL
Age : 4515sec
The output shows that Router C has two routes to reach network 1200::0/64: Router C<—>Router
B<—>Router A, which is the currently active route; Router C<—>Router D<—>Router A, which is
the backup route.
# Enable BFD debugging on Router C.
debugging bfd scm
debugging bfd event
debugging bgp bfd
terminal monitor
terminal debugging
# The following debugging information shows that Router C can quickly detect the failure on
Router B.
%Nov 5 11:42:24:172 2009 RouterC BFD/5/BFD_CHANGE_FSM:
Sess[3002::2/3001::1,13/17,GE3/1/1,Ctrl], Sta: UP->DOWN, Diag: 1
%Nov 5 11:42:24:172 2009 RouterC BGP/5/BGP_STATE_CHANGED: 3001::1 state is changed
from ESTABLISHED to IDLE.
*Nov 5 11:42:24:187 2009 RouterC RM/6/RMDEBUG: BGP_BFD: Recv BFD DOWN msg, Src IP
3002::2, Dst IP 3001::1, Instance ID 0.
*Nov 5 11:42:24:187 2009 RouterC RM/6/RMDEBUG: BGP_BFD: Reset BGP session 3001::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 3002::2, Dst IP 3001::1, Instance ID 0.
# Display route 1200::0/64 on Router C, and you can see that Router A and Router C
communicate through Router D.
display ipv6 routing-table 1200::0 64 verbose
Routing Table :
Summary Count : 1
Destination : 1200:: PrefixLength : 64
NextHop : 2001::1 Preference : 255
IpPrecedence : QosLcId :
RelayNextHop : FE80::223:89FF:FEEF:9A04 Tag : 0H
Neighbor : 2001::1 ProcessID : 0
Interface : GigabitEthernet3/1/2 Protocol : BGP4+
State : Active Adv GotQ Cost : 100
Tunnel ID : 0x0 Label : NULL
Age : 4635sec
The output shows that Router C has one route to reach network 1200::0/64, that is, Router
C<—>Router D<—>Router A.