Configuring Link Status Polling; Displaying And Maintaining Hdlc - HP MSR Router Series Wan Access Configuration Manual

Step
2. Enter synchronous-mode serial
interface view or POS
interface view.
3. Enable HDLC encapsulation
on the interface.

Configuring link status polling

An HDLC-enabled interface can regularly check link status by sending keepalives to the peer at the
keepalive interval at the link layer. A keepalive carries the local sender sequence number and the last
received sequence number of the peer.
After sending a keepalive, an interface increments the sender sequence number by 1 in the next
keepalive when the following conditions exist:
• The interface receives a response within the keepalive interval.
The response carries the sender sequence number in the sent keepalive.
•
After sending a keepalive, if the interface does not receive a response within the keepalive interval, it
resends the keepalive with an unchanged sequence number. When the keepalive retry limit is reached,
the interface considers the link faulty and reports a link layer down event.
When you configure link status polling, follows these restrictions and guidelines:
Link status check is disabled if you set the keepalive interval to 0.
•
HP recommends that you set the same keepalive interval for the two ends of a link.
•
• If the network has a long delay or is experiencing congestion, you can increase the keepalive
interval to prevent the link from being closed.
To configure link status polling:
Step
1. Enter system view.
2. Enter interface view.
3. Set the keepalive
interval.
4. Set the keepalive retry
limit.

Displaying and maintaining HDLC

Execute display commands in any view and reset commands in user view.
Task
Display the HDLC configuration
on an interface.
Command
interface interface-type
interface-number
link-protocol hdlc
Command
system-view
interface interface-type
interface-number
timer hold seconds
timer-hold retry retry
Command
display interface serial interface-number
display interface pos interface-number
97
Remarks
N/A
PPP encapsulation is enabled by
default.
Remarks
N/A
N/A
By default, the keepalive interval is 10 seconds.
By default, the keepalive retry limit is 5.