Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) - Manual (Page 118)

94 Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide
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Configuring MPLS
1
Brocade(config)# router mpls
Brocade(config-mpls)# policy
Brocade(config-mpls-policy)# traffic-engineering isis level-1
Syntax: [no] traffic-engineering isis level-1 | level-2
The level-1 option enables LSPs with TE extensions for the IS-IS level-1 domain.
The level-2 option enables LSPs with TE extensions for the IS-IS level-2 domain.
By default, the device does not send out IS-IS LSPs with TE extensions for its MPLS-enabled
interfaces. Since information in the TED is used to make path selections using CSPF, and
information in the TED comes from OSPF-TE LSAs or IS-IS LSPs with TE extensions, the user must
enable the device to send out OSPF-TE LSAs or IS-IS LSPs with TE extensions when the user wants
CSPF to perform constraint-based path selection.
Refer to “Setting traffic engineering parameters for MPLS interfaces” , for information on the traffic
engineering information carried in IS-IS LSPs with TE extensions.
Configuring CSPF interface constraint
As described in detail in
“Calculating a path based on an interface address” , under the default
condition, hops configured as interface addresses in an LSP path are resolved to the router ID.
Consequently, an LSP can be configured that does not traverse a specified interface. The
cspf-interface-constraint command was introduced that forces the CSPF calculation to include any
specified interface when creating an LSP. The operation and constraints of using this command are
described in the section mentioned.
The user can configure a Brocade device to always include a specified interface when forming an
LSP by configuring the cspf-interface-constraint command as shown in the following.
Brocade(config-mpls)# policy
Brocade(config-mpls-policy)# cspf-interface-constraint
Syntax: [no] cspf-interface-constraint
The default condition is for the CSPF interface Constraint feature to be disabled. When the feature
has been enabled, the user can use the [no] option to disable it.
The CSPF interface Constraint feature may be dynamically turned on or off. Turning the feature off
or on has no effect on LSPs that have already been established (primary and secondary). For LSPs
that are currently retried, changing the constraint setting changes the behavior on the next retry
such as when an LSP whose path is configured to use that interface fails to come up due to an
interface down condition.
Also note that the CSPF interface Constraint feature has significance for the ingress node only,
where the CSPF calculation takes place for an LSP or a detour segment.
Configuration changes to route filtering for MPLS and iBGP routes
LDP currently caches all routes known to the Routing Table Manager (RTM) except eBGP routes.
The following commands allows the user to control the number of routes cached in LDP, and the
type of route that MPLS accepts from the RTM.