MPLS Label Distribution Protocol, LDP – Part 5 (Export and Import Policy, Prefix Aggregation)

LDP and Export Policy

By default ALU only distribute a label only for its system addresses. To distribute additional other local prefixes, “export policy” is used.

You can find an “export-policy” example below:

A:>config router policy-options
	begin
	prefix-list “interface1”
		prefix 10.0.0.6/24
		exit
	policy-statement “LDP_Export_Policy1”
		entry 10
			from
				prefix-list “interface1”
				exit
			action accept
			exit
		exit
	exit
	commit

To apply this “export policy” to an LDP, use the below command:

A:>config router ldp export “LDP_Export_Policy1”

LDP and Import Policy

By default ALU accepts all labels form all peers. But with “import policy” certain label bindings can be rejected.

A:>config router policy-options
	begin
	policy-statement “LDP_Import_Policy1”
		entry 10
			action reject
			exit
		exit
	commit

To apply this “import policy” to an LDP use the below command:

A:>config router ldp export “LDP_Import_Policy1”

MPLS Label Distribution Protocol, LDP – Part 1
MPLS Label Distribution Protocol, LDP – Part 2
MPLS Label Distribution Protocol, LDP – Part 3 (Configuration on ALU)
MPLS Label Distribution Protocol, LDP – Part 4 (ECMP)
MPLS Label Distribution Protocol, LDP – Part 5 (Export and Import Policy, Prefix Aggregation)
MPLS Label Distribution Protocol, LDP – Part 6 (T-LDP)
MPLS Label Distribution Protocol, LDP – Part 7 (CR-LDP)

For more information about LDP, T-LDP and CR-LDP, check the related following RFCs…

RFC 5036: LDP Specification
RFC 3815: Definitions of Managed Objects for the MPLS,LDP
RFC 3478: Graceful Restart Mechanism for Label Distribution Protocol
RFC 5443: LDP IGP Synchronization
RFC 7307: LDP Extensions for Multi-Topology
RFC 7361: LDP Extensions for Optimized MAC Address Withdrawal in a H-VPLS
RFC 3212: Constraint-Based LSP Setup using LDP
RFC 3213: Applicability Statement for CR-LDP 
RFC 3214: LSP Modification Using CR-LDP

…YOU CAN REACH ALL THE “MPLS” ARTICLES AND CONFIGURATIONS BELOW…

MPLS Basics
What is MPLS?
Enabling MPLS on Cisco Router

MPLS Label Distribution Protocol, LDP
MPLS Label Distribution Protocol, LDP – Part 1
MPLS Label Distribution Protocol, LDP – Part 2
MPLS Label Distribution Protocol, LDP – Part 3 (Configuration on ALU)
MPLS Label Distribution Protocol, LDP – Part 4 (ECMP)
MPLS Label Distribution Protocol, LDP – Part 5 (Export and Import Policy, Prefix Aggregation)
MPLS Label Distribution Protocol, LDP – Part 6 (T-LDP)
MPLS Label Distribution Protocol, LDP – Part 7 (CR-LDP)

MPLS, RSVP-TE
MPLS, RSVP-TE – Part 1
MPLS, RSVP-TE – Part 2(Alcatel-Lucent Configuration)

MPLS Protection And Restoration
MPLS Protection and Restoration – Part 1
MPLS Protection and Restoration – Part 2 (End-to-End Protection, Secondary Paths)
MPLS Protection and Restoration – Part 3 (Path Diversity in Secondary Paths)
MPLS Protection and Restoration – Part 4 (Local Protection, Fast Reroute)
MPLS Protection and Restoration – Part 5 (Fast Reroute Protection Types)
MPLS Protection and Restoration – Part 6 (RSVP Objects Used for MPLS Fast Reroute)
MPLS Protection and Restoration – Part 7 (Verification Commands on Alcatel-Lucent Routers)
MPLS Protection and Restoration – Part 8 (Actions After the Failure)
MPLS Protection and Restoration – Part 9 (Convergence Factors)
MPLS Protection and Restoration – Part 10 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 11 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 12 (Juniper Configuration Samples)
MPLS Protection and Restoration – Part 13 (Juniper Configuration Samples)