Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) - Manual (Page 350)

326 Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide
53-1003031-02
Label withdrawal delay
2
Total number of prefix FECs: 6
Total number of prefix FECs installed: 1
Total number of prefix FECs filtered (in/out): 2/2
Destination State Out-intf Next-hop Ingress Egress Filtered
192.168.1.1/32 current e2/1 10.23.23.12 Yes No In
192.168.1.2/32 current e2/1 10.23.23.12 Yes No In
192.168.1.3/32 current e2/1 10.23.23.12 Yes No Out
192.168.1.4/32 current e2/1 10.23.23.12 Yes No Out
Brocade# show mpls ldp fec prefix filtered in
Total number of prefix FECs: 6
Total number of prefix FECs installed: 1
Total number of prefix FECs filtered (in/out): 2/2
Destination State Out-intf Next-hop Ingress Egress Filtered
192.168.1.1/32 current e2/1 10.23.23.12 Yes No In
192.168.1.2/32 current e2/1 10.23.23.12 Yes No In
Brocade# show mpls ldp fec prefix filtered out
Total number of prefix FECs: 6
Total number of prefix FECs installed: 1
Total number of prefix FECs filtered (in/out): 2/2
Destination State Out-intf Next-hop Ingress Egress Filtered
192.168.1.3/32 current e2/1 10.23.23.12 Yes No Out
192.168.1.4/32 current e2/1 10.23.23.12 Yes No Out
History
Release Command history
Multi-Service NetIron Release 05.600 The filtered options on the show mpls ldp fec prefix command now
includes lists of both, FECs filtered due to inbound and outbound FEC
filtering configuration.
Related
commands
None.
Label withdrawal delay
The label withdrawal timer delays sending a label withdraw message for a FEC to a neighbor.
When an LDP session fails, the label associated with a FEC is withdrawn from all upstream peers.
In addition, if the IGP adjusts the route for the FEC such that the current neighbor is no longer the
next hop for the FEC, then the associated FEC label is withdrawn from all upstream peers.
The label withdrawal delay timer introduces a configurable delay to allow the IGP and LDP to
converge after these events. The delay helps avoid sending the label withdraw message to the
upstream peers. For example, after a link failure, instead of immediately sending a label withdraw
to all upstream peers for the FEC; the delay allows the IGP to install a route which may match
another existing downstream session. Label withdrawal from all upstream peers can be avoided if
the FEC achieves a downstream label mapping which is consistent with the IGP routing table.
If the timer expires, the FEC label is then withdrawn from all upstream peers.