Network requirements – H3C Technologies H3C SecPath F1000-E User Manual
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Figure 26 Verify the configuration result
Configuration Example for P2MP GRE Tunnel Backup at the
Headquarters
Network requirements
As shown in
, the headquarters uses two gateways at the egress of the internal network, with
Device B for backup. Two GRE tunnels are created on Device C, the gateway at the branch, one for
connecting Device A and the other for connecting Device B. Normally, packets are forwarded along the
tunnel between Device A and Device C. When a failure occurs along this path, the tunnel between
Device B and Device C is used to transmit packets.
To meet the above requirements, you need to establish a P2MP GRE tunnel with the branch on both
Device A and Device B, establish a GRE over IPv4 tunnel between Device A and Device B, and on Device
A, configure the tunnel interface of the GRE over IPv4 tunnel as the backup interface of the P2MP GRE
tunnel interface. Thus, when Device A cannot find the corresponding tunnel entry for a packet, it delivers
the packet to Device B, which then forwards the packet to Device C.
NOTE:
To avoid looping, do not configure the tunnel interface of the GRE over IPv4 tunnel as the backup interface
of the P2MP GRE tunnel interface on Device B.