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Configuring MPLS LSP ping
MPLS LSP ping can be used to check the connectivity of an MPLS TE tunnel. At the ingress, it adds the
label of the tunnel into an MPLS echo request, and sends it along the MPLS TE tunnel to the egress. The
ingress determines whether the MPLS TE tunnel is normal according to whether it can receive a reply from
the egress.
To check the connectivity of an MPLS TE tunnel:
To do…
Use the command…
Remarks
Use MPLS LSP ping to check the
connectivity of an MPLS TE tunnel
ping lsp
[
-a
source-ip
|
-c
count
|
-exp
exp-value
|
-h
ttl-value
|
-m
wait-time
|
-r
reply-mode
|
-s
packet-size
|
-t
time-out
|
-v
]
*
te
interface-type interface-number
Required
Available in any view
Configuring MPLS LSP tracert
MPLS LSP tracert can be used to locate errors of an MPLS TE tunnel. It sends MPLS echo requests to the
nodes along the MPLS TE tunnel to be inspected, with the TTL increasing from 1 to a specific value. Each
node along the MPLS TE tunnel will return an MPLS echo reply to the ingress due to TTL timeout. Thus, the
ingress can collect the information of each hop along the MPLS TE tunnel, so as to locate the failed node.
You can also use MPLS LSP tracert to collect important information of each hop along the MPLS TE tunnel,
such as the label allocated.
To locate errors of an MPLS TE tunnel:
To do…
Use the command…
Remarks
Use MPLS LSP tracert to locate
errors of an MPLS TE tunnel
tracert lsp
[
-a
source-ip
|
-exp
exp-value
|
-h
ttl-value
|
-r
reply-mode
|
-t
time-out
]
*
te
interface-type interface-number
Required
Available in any view
Configuring BFD for an MPLS TE tunnel
You can configure BFD for an MPLS TE tunnel to implement fast detection of the connectivity of the tunnel.
After you configure BFD for an MPLS TE tunnel, a BFD session will be established between the ingress
and egress of the tunnel, and the ingress will add the label for the tunnel into a BFD control packet,
forward the BFD control packet along the tunnel, and determine the status of the tunnel according to the
BFD control packet received from the egress. Upon detecting an MPLS TE tunnel failure, BFD triggers
protection switching to switch traffic to another tunnel.
A BFD session for MPLS TE tunnel detection can be static or dynamic.
•
Static: If you specify the local and remote discriminator values by using the
discriminator
keyword
when configuring the
mpls te
bfd enable
command, the BFD session will be established with the
specified discriminator values. Such a BFD session can detect the connectivity of a pair of MPLS TE
tunnels in opposite directions (one from local to remote, and the other from remote to local) between
two devices.
•
Dynamic: If you do not specify the local and remote discriminator values when configuring the
mpls
te
bfd enable
command, the MPLS LSP ping will be run automatically to negotiate the discriminator
values and then the BFD session will be established based on the negotiated discriminator values.