Detecting next hop reachability through bfd, Network requirements, Configuration procedure – H3C Technologies H3C SR8800 User Manual

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8

Step Command

Remarks

2.

Configure the
default preference

for static routes.

ip route-static default-preference default-preference-value

Optional.
60 by default.

NOTE:

When you configure a static route, the static route does not take effect if you specify the next hop address
first and then configure it as the IP address of a local interface, such as Ethernet interface and VLAN

interface.

If you do not specify the preference when configuring a static route, the default preference will be used.
Reconfiguring the default preference applies only to newly created static routes.

You can flexibly control static routes by configuring tag values and using the tag values in the routing
policy.

If the destination IP address and mask are both configured as 0.0.0.0 with the ip route-static command,
the route is the default route.

For detailed information about track, see

High Availability Configuration Guide.

Detecting reachability of the static route’s next hop

If a static route fails due to a topology change or a fault, traffic over the route is interrupted. To improve

reliability, the system must detect the reachability of the static route’s next hop and switch to a backup

route once the next hop is unreachable.
There are two methods for this purpose. Only one of the two methods can be used at a time.

Detecting next hop reachability through BFD

Bidirectional forwarding detection (BFD) provides a general-purpose, standard, medium- and

protocol-independent fast failure detection mechanism. It can uniformly and quickly detect the failures of

the bidirectional forwarding paths between two routers for upper-layer protocols, such as routing

protocols and Multiprotocol Label Switching (MPLS). For more information about BFD, see High

Availability Configuration Guide.
After a static route is configured, you can enable BFD to detect the reachability of the static route's next

hop.

Network requirements

To detect the reachability of the static route's next hop through BFD, you must enable BFD first. For BFD
configuration, see High Availability Configuration Guide.

Configuration procedure

To detect reachability of the static route’s next hop through BFD:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

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