379 
 
 Destination : 2001:4::1                               PrefixLen: 128 
 Flag        : R/-/-                                   Cost     : 10 
 Next Hop    : FE80::20F:E2FF:FE3E:FA3D                Interface: Eth1/3 
 
      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set 
# Display the IPv6 IS-IS routing table on Router D.  
[RouterD] display isis route ipv6 
 
                         Route information for IS-IS(1) 
                         ------------------------------ 
 
                         Level-2 IPv6 Forwarding Table 
                         ----------------------------- 
 Destination : 2001:1::                                PrefixLen: 64 
 Flag        : R/-/-                                   Cost     : 20 
 Next Hop    : FE80::200:FF:FE0F:4                     Interface: Eth1/1 
 
 Destination : 2001:2::                                PrefixLen: 64 
 Flag        : R/-/-                                   Cost     : 20 
 Next Hop    : FE80::200:FF:FE0F:4                     Interface: Eth1/1 
 
 Destination : 2001:3::                                PrefixLen: 64 
 Flag        : D/L/-                                   Cost     : 10 
 Next Hop    : Direct                                  Interface: Eth1/1 
 
 Destination : 2001:4::1                               PrefixLen: 128 
 Flag        : D/L/-                                   Cost     : 0 
 Next Hop    : Direct                                  Interface: Eth1/2 
 
      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set 
BFD for IPv6 IS-IS configuration example 
Network requirements 
•  As shown in Figure 93, configure IPv6 IS-IS on Router A, Router B, and Router C so that they can 
reach each other. 
•  Enable BFD on Ethernet 1/1 of Router A and Router B. When the link between Router B and the 
Layer-2 switch fails, BFD can quickly detect the failure and notify IPv6 IS-IS of the failure. Then Router 
A and Router B communicate through Router C.