LDP Hello interval and Hello Hold timeout timers

The LDP Hello interval and Hello Hold Timeout timers are used to establish Hello Adjacency between peers. The Hello interval is the time period between which the LSR sends out Hello messages and the Hello Hold timeout is the amount of time that the sending LSR maintains its record of Hellos from the receiving LSR without receipt of another Hello message.

The Hello interval and Hello Hold Timeout timer values can be obtained from the global default values or configured globally on a router. The Hello Hold timeout timer value can also be configured through an interface. When configuring these values the following constraints must be followed:

• The Hello Interval value must be less than 32767.
• The Hello Hold Timeout value must be less than 65535.
• The Hello Hold Timeout value must be greater than or equal to 2 times the Hello Interval value.

The values can be set that determine the values used on the configured router and values sent to adjacent peers for their configuration as follows:

• Setting the LDP Hello interval values
• Setting the LDP Hold time sent to adjacent LSRs
• Determining the LDP Hold time on an MPLS interface