Juniper JUNOSE SOFTWARE 11.2.X - LINK LAYER CONFIGURATION GUIDE 7-7-2010 Configuration Manual page 539

hdlc keepalive
hdlc shutdown
Copyright © 2010, Juniper Networks, Inc.
Use to enable loopback detection on a Cisco HDLC interface.
By default, loopback detection is disabled.
Example
host1(config-if)#hdlc down-when-looped
Use the no version to disable loopback detection on a Cisco HDLC interface.
See hdlc down-when-looped.
Use to specify the keepalive timeout value.
When the keepalive timer expires, the interface increments its own counter; then it
compares the value of this counter with the last value received from a peer. If the
difference between the values of the two counters is greater than three, the Cisco
HDLC interface is declared down. After that, the interface sends a keepalive message
containing the value of its counter and the last received value of the peer's counter.
The router stores the values received in keepalive messages from a peer interface. If
the interface is down, the router compares the received value of its own counter with
the value from the peer. If the difference between the values of the two counters is
less than four, the router declares the interface to be up. Both sides have to configure
the same value for the keepalive interval.
If the keepalive interval is 10 seconds, then a failed link is detected between 30 and
40 seconds after failure.
The range is 0–6553 seconds. A value of 0 turns keepalive off.
The default is 10 seconds.
Example
host1(config-if)#hdlc keepalive 10
Use the no version to turn off the keepalive feature.
See hdlc keepalive.
Use to terminate a Cisco HDLC session.
This command administratively disables the interface.
Example
host1(config-if)#hdlc shutdown
Use the no version to restart a disabled session. The default for each hdlc shutdown
command is the no version.
See hdlc shutdown.
Chapter 16: Configuring Cisco HDLC
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