118 
  OrigTblID: 0x0                OrigVrf: default-vrf 
    TableID: 0x2                 OrigAs: 0 
      NBRID: 0x26000002          LastAs: 0 
     AttrID: 0xffffffff        Neighbor: 0.0.0.0 
      Flags: 0x1008c        OrigNextHop: 10.1.1.100 
      Label: NULL           RealNextHop: 10.1.1.100 
    BkLabel: NULL             BkNextHop: N/A 
  Tunnel ID: Invalid          Interface: Ethernet1/2 
BkTunnel ID: Invalid        BkInterface: N/A 
The output shows that Router A communicates with Router B through Ethernet 1/2. 
OSPF FRR configuration example 
Network requirements 
As shown in Figure 31, Router S, Router A, and Router D reside in the same OSPF domain. Configure 
OSPF FRR so that when Link A fails, traffic is immediately switched to Link B. 
Figure 31 Network diagram 
 
 
Configuration procedure 
1.  Configure IP addresses and subnet masks for interfaces on the routers. (Details not shown.) 
2.  Configure OSPF on the routers to make sure Router S, Router A, and Router D can communicate 
with each other at the network layer. (Details not shown.) 
3.  Configure OSPF FRR: 
You can enable OSPF FRR to either calculate a backup next hop by using the LFA algorithm, or 
specify a backup next hop by using a routing policy. 
{  (Method 1.) Enable OSPF FRR to calculate a backup next hop by using the LFA algorithm: 
# Configure Router S.  
<RouterS> system-view 
[RouterS] bfd echo-source-ip 1.1.1.1 
[RouterS] ospf 1 
[RouterS-ospf-1] fast-reroute lfa 
[RouterS-ospf-1] quit 
# Configure Router D.  
<RouterD> system-view 
[RouterD] bfd echo-source-ip 4.4.4.4 
[RouterD] ospf 1 
[RouterD-ospf-1] fast-reroute lfa