Configuring is-is te – H3C Technologies H3C SR8800 User Manual

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Step Command

Remarks

6.

Return to OSPF view.

quit

N/A

NOTE:

For more information about OSPF opaque LSA, see

Layer 3—IP Routing Configuration Guide.

MPLS TE cannot reserve resources and distribute labels on OSPF virtual links. MPLS TE cannot establish
an LSP tunnel through an OSPF virtual link. Make sure no virtual links exist in the OSPF routing domain
when configuring OSPF TE.

Configuring IS-IS TE

Configure IS-IS TE if the routing protocol is IS-IS and a dynamic signaling protocol is used for MPLS TE
tunnel setup. In case both OSPF TE and IS-IS TE are available, OSPF TE takes priority.
The IS-IS TE extension uses the sub-TLV of IS reachability TLV (type 22) to carry TE attributes. Before

configuring IS-IS TE, you need to configure the IS-IS wide metric style, which can be wide, compatible, or

wide-compatible.

CAUTION:

According to RFC 3784, the length of the IS reachability TLV (type 22) may reach the maximum of 255
octets in some cases.

For an IS-IS LSP to carry this type of TLV and to be flooded normally on all interfaces with IS-IS enabled,
the MTU of any IS-IS enabled interface, including 27 octets of LSP header and two octets of TLV header,
cannot be less than 284 octets. If an LSP must also carry the authentication information, the minimum

MTU needs to be recalculated according to the packet structure.

When TE is configured, H3C recommends that you set the MTU of any interface with IS-IS enabled be
equal to or greater than 512 octets to guarantee that IS-IS LSPs can be flooded on the network.

To configure IS-IS TE:

Step Command

Remarks

1.

Enter system view.

system-view

––

2.

Enter IS-IS view.

isis [ process-id ] ––

3.

Configure the wide metric

attribute of IS-IS.

cost-style { narrow | wide |
wide-compatible | { compatible |

narrow-compatible }

[ relax-spf-limit ] }

By default, IS-IS uses narrow metric
style.

4.

Enable IS-IS TE.

traffic-eng [ level-1 | level-2 |
level-1-2 ]

Disabled by default.

5.

Configure the TLV type of the

sub-TLV carrying DS-TE
parameters.

te-set-subtlv { bw-constraint value
| lo-multiplier value |

unreserved-bw-sub-pool value }

Optional.
By default, the bw-constraint
parameter is carried in sub-TLV

252; the lo-multiplier parameter in
sub-TLV 253; and the

unreserved-bw-sub-pool

parameter in sub-TLV 251.

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