3Com MSR 50 Series Configuration Manual page 1376

1376 C 77: MPLS TE C
HAPTER ONFIGURATION
Forwarding traffic along MPLS TE tunnels through automatic route
advertisement
Two approaches, IGP shortcut and forwarding adjacency, are available to
automatic route advertisement to advertise MPLS TE tunnel interface routes to
IGPs, allowing traffic to be routed down MPLS TE tunnels.
In either approach, TE tunnels are considered point-to-point links and TE tunnel
interfaces can be set as outgoing interfaces.
IGP shortcut and forwarding adjacency are different in that in the forwarding
adjacency approach, routes with TE tunnel interfaces as outgoing interfaces are
advertised to neighboring devices but not in the IGP shortcut approach. Therefore,
TE tunnels are visible to other devices in the forwarding adjacency approach but
not in the IGP shortcut approach.
You may assign a metric, either absolute or relative, to TE tunnels for the purpose
of path calculation in either approach. If it is absolute, the metric is directly used
for path calculation. If it is relative, the cost of the corresponding IGP path must be
added to the metric before it can be used for path calculation.
1 Configure IGP shortcut
Follow these steps to configure IGP shortcut:
To do...
Enter system view
Enter MPLS TE tunnel
interface view
Configure the IGP to take the
MPLS TE tunnels in up state
into account when
performing enhanced SPF
calculation
Assign a metric to the MPLS
TE tunnel
Submit current tunnel
configuration
Exit to system view
Enter IS-IS view
Enter OSPF view
Enable the IGP shortcut
function
2 Configure forwarding adjacency
Follow these steps to configure forwarding adjacency:
Use command to...
system-view
interface tunnel
tunnel-number
mpls te igp shortcut [ isis |
ospf ]
mpls te igp metric
{ absolute | relative } value
mpls te commit
quit
isis [ process-id ]
ospf [ process-id ]
enable traffic-adjustment
Remarks
--
--
Required
MPLS TE tunnels are not
considered in the enhanced
SPF calculation of IGP.
If no IGP type is specified, the
configuration applies to both
OSPF and IS-IS by default.
Optional
The metrics of TE tunnels
equal the metrics of their
corresponding IGP routes by
default.
Required
--
--
Required
Disabled by default