Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) - Manual (Page 241)

Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide 217
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MPLS LDP-IGP synchronization
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Configuring MPLS LDP-IGP synchronization
This section contains the following tasks:
• Configuring MPLS LDP-IGP synchronization with OSPF interfaces (required).
• Selectively Disabling MPLS LDP-IGP synchronization from some OSPF interfaces (optional).
• Verifying MPLS LDP-IGP synchronization with OSPF (optional).
NOTE
Brocade recommends configuring the hold-down timer to more than 60 seconds to avoid traffic loss.
Configuring MPLS LDP-IGP synchronization globally
MPLS LDP-IGP synchronization is disabled by default. To globally enable MPLS LDP-IGP
synchronization with IS-IS, enter the following commands:
Brocade(config)# router isis
Brocade(config-isis-router)# address-family ipv4 unicast
Brocade(config-isis-router-router-ipv4u)# metric-style wide
Brocade(config-isis-router-router-ipv4u)# ldp-sync
Brocade(config-isis-router-router-ipv4u)# exit
Brocade(config-isis-router)#
MPLS LDP-IGP synchronization is disabled by default. To globally enable MPLS LDP-IGP
synchronization with OSPF, enter the following commands.
Brocade(conf)# router ospf
Brocade(conf-ospf-router)# ldp-sync
Brocade(conf-ospf-router)#
Syntax: [no] ldp-sync
Setting the LDP IGP sync hold down time
The ldp-sync hold-down command sets the LDP-IGP sync hold down time. The hold down time (in
router OSPF and the router IS-IS modes) is the interval which the IGP advertises the maximum IP
metric, while waiting for an update from LDP.
The hold down interval starts whenever the IGP initially is enabled with LDP-IGP sync. It is also
started whenever LDP updates the IGP with an update indicating the interface status, from LDP's
perspective, is not-in-sync. When the hold down time expires, the IGP resumes advertising the
normal metric for the link.
When hold down time is configured (from no hold down time), the router starts the hold-down-timer
on every interface that is not-in-sync at the time.
When hold down time is un-configured, the router stops the hold-down-timer on every interface that
has hold-down-timer running at the time as if there is no hold down time configured. As a result,
these interfaces have infinite hold down time. For those not-in-sync interfaces with hold-down time
already expired, IGP will continues to advertise normal metric.
By default, hold-down time is disabled. IGP waits until LDP gives an in-sync indication for the link
before it advertised the normal metric.