Configuring LDP FEC Deaggregation
Beginning with JUNOSe Release 8.1.0, LDP routers running JUNOSe employ LDP FEC aggregation by default. FEC aggregation means that when an LDP egress router advertises multiple prefixes, all the prefixes are members of the same FEC. Only a single label is advertised for this FEC. LDP maintains this aggregation as the advertisement traverses the network, if possible.
Consider the topology shown in Figure 59.
In this example, LSR 2 uses FEC aggregation, but LSR 3 does not. Consequently, LSR 2 advertises the single label e, mapped to a FEC that includes both prefixes, 10.10.22.0/24 and 10.43.12.0/24.
In contrast, LSR 3 has two FECs, one for 10.10.22.0/24 and one for 10.43.12.0/24. A separate label is bound to each FEC. LSR 3 advertises label h for one FEC and label w for the other FEC.
LSR 2 and LSR 3 are downstream routers for LSR 1. LSR 1 does not aggregate. Instead, LSR 1 advertises label d for 10.10.22.0/24 and label x for 10.43.12.0/24.
mpls ldp deaggregate
- Use to bind each prefix on the current virtual router to a separate label.
- Earlier versions of the JUNOSe software do not support FEC aggregation. When interoperating with routers running such a release, you must issue this command
- Issuing this command automatically creates LDP or MPLS on the current virtual router if they do not yet exist there.
- This command takes effect immediately.
- Example
host1(config)#mpls ldp deaggregate