Requirements Analysis; Software Version Used; Configuration Restrictions And Guidelines; Configuration Procedures - H3C S12500 Configuration Examples

Figure 2 Network diagram

Requirements analysis

To make sure Link B is a backup for Link A, configure a greater cost for Link B.
To make sure Switch S can immediately detect failures on the link between Switch S and Switch A,
enable BFD on Switch S.
To make sure Link B takes effect immediately when Link A fails, enable FRR on Switch S by using the
fast-reroute auto command or by using a routing policy. When you enable OSPF FRR to designate a
backup next hop by using a routing policy:
To allow only matching packets to be switched to the backup link, specify an IP prefix list.
•
• To configure the backup route for link switchover, specify both the output interface and next hop
of the route in the routing policy.

Software version used

This configuration example was created and verified on S12500-CMW520-R1825P01.

Configuration restrictions and guidelines

When you configure OSPF FRR, follow these restrictions and guidelines:
• Do not use OSPF FRR and OSPF BFD at the same time.
Do not use the fast-reroute auto command together with the commands vlink-peer, sham-link,
•
enable traffic-adjustment, and enable traffic-adjustment advertise.

Configuration procedures

1. Configure IP addresses for interfaces and enable OSPF on the switches:
# Configure the IP address and subnet mask for each interface, as shown in
not shown.)
6
Figure 2. (Details