67
Step Command
Remarks
3.
Specify the type of the label to
be distributed by the egress to
the penultimate hop.
label advertise
{
explicit-null
|
implicit-null
|
non-null
}
Optional.
By default, an egress distributes to
the penultimate hop an implicit null
label.
Configuring the policy for triggering LSP establishment
You can configure an LSP triggering policy on an LSR, so only routes matching the policy can trigger
establishment of LSPs, reducing the number of LSPs to be established on the LSR and avoiding instability
of the LSR caused by excessive LSPs.
An LSR supports the following types of LSP triggering policies:
•
Allowing all routing entries to trigger establishment of LSPs.
•
Filtering routing entries by an IP prefix list, so static and IGP routes denied by the IP prefix list do not
trigger LSP establishment. To use this policy, first create the IP prefix list. For information about IP
prefix list configuration, see
Layer 3—IP Routing Configuration Guide
.
To configure the policy for triggering LSP establishment:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter MPLS view.
mpls
N/A
3.
Configure the LSP
establishment triggering
policy.
lsp-trigger
[
vpn-instance
vpn-instance-name
] {
all
|
ip-prefix
prefix-name
}
Optional.
By default, only host routes with
32-bit masks can trigger
establishment of LSPs.
If the
vpn-instance
vpn-instance-name
option is
specified, the command configures
an LSP establishment triggering
policy for the specified VPN.
Otherwise, the command
configures an LSP establishment
triggering policy for the public
network routes.
NOTE:
For an LSP to be established, an exactly matching routing entry must exist on the LSR. For example, on an
LSR, to establish an LSP to a loopback address with a 32-bit mask, there must be an exactly matching host
routing entry on the LSR.
Configuring the label distribution control mode
With the label re-advertisement function enabled, an LSR periodically looks for FECs not assigned with
labels, assigns labels to them if any, and advertises the label-FEC bindings. You can set the label
re-advertisement interval as needed.
