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Configuring IS-IS TE
IS-IS TE uses a sub-TLV of the extended IS reachability TLV (type 22) to carry TE attributes.
Because the extended IS reachability TLV carries wide metrics, specify a wide metric-compatible
metric style for the IS-IS process before enabling IS-IS TE. Available metric styles for IS-IS TE
include wide, compatible, or wide-compatible. For more information about IS-IS, see
Layer 3—IP
Routing Configuration Guide
.
On IS-IS enabled interfaces, set the MTU to a minimum of 512 bytes to ensure that IS-IS LSPs of
different lengths can be flooded to the network.
To configure IS-IS TE:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Create an IS-IS process
and enter IS-IS view.
isis
[
process-id
]
By default, no IS-IS process exists.
3.
Specify a metric style.
cost-style
{
narrow
|
wide
|
wide-compatible
| {
compatible
|
narrow-compatible
}
[
relax-spf-limit
] }
By default, only narrow metric style
packets can be received and sent.
For more information about this
command, see
Layer 3—IP Routing
Command Reference
.
4.
Enable MPLS TE for the
IS-IS process.
mpls te enable
[
Level-1
|
Level-2
]
By default, MPLS TE is disabled for
an IS-IS process.
5.
Specify the types of the
sub-TLVs for carrying
DS-TE parameters.
te-subtlv
{
bw-constraint
value
|
unreserved-subpool-bw
value
}
*
By default, the
bw-constraint
parameter is carried in sub-TLV
252, and the
unreserved-bw-sub-pool
parameter is carried in sub-TLV
251.
Configuring MPLS TE tunnel constraints
Perform this task on the ingress node of the MPLS TE tunnel.
Configuring bandwidth constraints for an MPLS TE tunnel
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter MPLS TE tunnel
interface view.
interface tunnel
tunnel-number
[
mode
mpls-te
]
N/A
3.
Configure bandwidth
required for the tunnel, and
specify a CT for the tunnel's
traffic.
mpls te bandwidth
[
ct0
|
ct1
|
ct2
|
ct3
]
bandwidth
By default, no bandwidth is
assigned, and the class type is CT
0.
Configuring the affinity attribute for an MPLS TE tunnel
The associations between the link attribute and the affinity attribute might vary by vendor. To ensure
the successful establishment of a tunnel between two devices from different vendors, correctly
configure their respective link attribute and affinity attribute.
To configure the affinity attribute for an MPLS TE tunnel: