Modifying the Keepalive Interval
When the keepalive feature is enabled, a keepalive packet is sent at the specified time interval to keep the
interface active. The keepalive interval
must
be configured to be the same on both ends of the POS link.
To modify the keepalive interval, use the following command in interface configuration mode:
Purpose
Command
Specifies the frequency at which the Cisco IOS
software sends messages to the other end of the link,
to ensure that a network interface is alive, where:
•
period
—
Specifies the time interval in seconds
for sending keepalive packets. The default is 10
seconds.
•
retries
—
Specifies the number of times that the
device will continue to send keepalive packets
without response before bringing the interface
down. The default is 5 retries.
Router(config-if)#
keepalive
[
period
[
retries
]]
To disable keepalive packets, use the
no
form of this command.
If keepalives are enabled and you are trying to configure line loopback on a POS interface, the keepalive
protocol will fail and periodically reset the interface based on the keepalive timeout and cause Layer 1
errors on the other end of the link that is trying to do the loopbacks.You can avoid this by using the no
keepalive command on the POS interface that is configured for line loopback. The side that is not in line
loopback detects that its keepalive is being looped back and functions properly. An interface configured
for internal loopback also functions properly with keepalives enabled.
Note
Verifying the Keepalive Interval
To verify the keepalive interval, use the
show interfaces pos
privileged EXEC command and observe the
value shown in the
“
Keepalive
”
field.
The following example shows that keepalive is enabled for interface port 0 on the POS SPA installed in subslot
0 of the SIP that is located in chassis slot 2 of the Cisco ASR 1000 Series Router:
Router#
show interfaces pos 2/0/0
POS2/0/0 is up, line protocol is up
Hardware is Packet over SonetInternet address is 10.1.1.1.2MTU 9216 bytes, BW 622000 Kbit,
DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255
Keepalive set (10 sec.)
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
OL-14127-17
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Configuring the POS SPAs
Modifying the Keepalive Interval