R0106-HP MSR Router Series Layer 2 - WAN Command Reference(V7)

Parameters

seconds: Specifies the link status polling interval (in seconds), in the range 0 to 32767.

Usage guidelines

HDLC can regularly check link status. If an interface uses HDLC as the link layer protocol, the link layer

sends keepalives to the peer at an interval specified by the timer-hold command. A keepalive carries the

local sending sequence number and the previous sending sequence number of the peer.

When an interface receives a keepalive that carries its previous sending sequence number, it increments

the previous sending sequence number by 1 in the next keepalive. Otherwise, it uses the previous

sending sequence number. If an interface fails to receive keepalives carrying its previous sending

sequence number within five polling intervals, it performs the following tasks:

• Considers the link faulty.

• Reports a link layer down event.

Setting the link status polling interval to 0 disables link status check.

HP recommends that you set the same interval for the two ends of a link.

If the network has a long delay or is experiencing congestion, you can increase the polling interval to

prevent the link from being closed.

Examples

# Set the link status polling interval to 100 seconds on interface Serial 2/1/0.

<Sysname> system-view

[Sysname] interface serial 2/1/0

[Sysname-serial2/1/0] timer-hold 100