Huawei AR2200-S Series Configuration Manual page 152

Huawei AR2200-S Series Enterprise Routers
Configuration Guide - Reliability
Context
Perform the following procedure on both ends of a link to be checked:
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Select one of the following steps based on the type of link checked by BFD:
l On a Layer 3 interface with an IP address, run:
l On a Layer 2 interface, Layer 3 interface, or a Layer 3 sub-interface, run:
Step 3 Configure discriminators by running the following commands:
l To configure a local discriminator, run:
l To configure a remote discriminator, run:
Step 4 Run:
Issue 01 (2012-01-06)
bfd cfg-name bind peer-ip peer-ip [ vpn-instance vpn-instance-name ] interface
interface-type interface-number [ source-ip source-ip ]
– If a single-hop BFD session is to be set up on an interface for the first time, the interface
and its peer address must be bound to the BFD session. The bindings cannot be modified
after the BFD session is successfully created.
– During BFD configuration items are being created, the system checks only the format,
not the correctness, of an IP address. Either an incorrect peer or source IP address leads
to a failure in creating a BFD session.
– If BFD and Unicast Reverse Path Forwarding (URPF) are used together, as URPF checks
the source IP address of received packets, configure source-ip to specify a correct source
IP address for BFD packets during the creation of a BFD binding; otherwise, BFD packets
are discarded mistakenly.
NOTE
A BFD session currently does not detect route switching. If the change of bound peer IP address causes
a route to switch to another link, the BFD session is negotiated again only when the original link fails.
bfd cfg-name bind peer-ip default-ip interface interface-type interface-number
[ source-ip source-ip ]
A multicast BFD session is created.
NOTE
Before creating a multicast BFD session on a Layer 3 interface or a Layer 3 sub-interface, configure
an IP address for the interface to ensure that the network layer protocol status of the interface is Up. If
no IP address is configured for the interface, no multicast BFD session can be established.
discriminator local discr-value
discriminator remote discr-value
NOTE
l The local discriminator set on a device is equal to the remote discriminator set on a remote device, and
the remote discriminator set on the local device is equal to the local discriminator set on the remote
device. If the local and remote discriminators do not match, the session cannot be created. After the
local and remote discriminators are set, they cannot be changed.
l If a default multicast address is bound to a BFD session, the local and remote discriminators of the
session must be different.
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3 BFD Configuration
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