LDP FRR configuration example
Network requirements
Router S, Router A, and Router D reside in the same OSPF domain. Configure OSPF FRR so LDP can
establish a primary LSP and a backup LSP on the Router S—Router D and the Router S—Router A—Router
D links, respectively.
When the primary LSP operates correctly, traffic between subnets 1 1.1.1.0/24 and 21.1.1.0/24 is
forwarded through the LSP.
When the primary LSP fails, traffic between the two subnets can be immediately switched to the backup
LSP.
Figure 20 Network diagram
Requirements analysis
To ensure that the LSRs establish LSPs automatically, enable LDP on each LSR.
•
To establish LDP LSPs, configure a routing protocol to ensure IP connectivity between the LSRs. This
•
example uses OSPF.
To ensure that LDP establishes LSPs only for the routes 1 1.1.1.0/24 and 21.1.1.0/24, configure LSP
•
generation policies on each LSR.
•
To allow LDP to establish backup LSRs, configure OSPF FRR on Router S and Router D.
Configuration procedure
1.
Configure IP addresses and masks for interfaces, including the loopback interfaces, as shown
in
Figure
2.
Configure OSPF on each router to ensure IP connectivity between them. (Details not shown.)
3.
Configure OSPF FRR by using one of the following methods:
(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 10.10.10.10
[RouterS] ospf 1
[RouterS-ospf-1] fast-reroute lfa
[RouterS-ospf-1] quit
20. (Details not shown.)
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