beautypg.com

Customizing a polling instance – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual

Page 2056

background image

Ping Polling Introduction and Configuration

Software Reference for x310 Series Switches

78.6

AlliedWare Plus

TM

Operating System - Version 5.4.4C

C613-50046-01 REV A

Customizing a Polling Instance

Once you’ve created a polling instance using the

ping-poll

and

ip (ping-polling)

command, you may wish to customize the polling instance for your network.

Packet size

If you find that larger packet types in your network are not reaching the polled device
while smaller ones such as ping do, you can increase the data bytes included in the ping
packets sent by the polling instance. This encourages the polling instance to change the
device’s status to unreachable when packet of the size you are interested in are being
dropped. To change the number of bytes sent in the data portion of the ping packets, use
the command:

Response timeout

The polling instance determines that a device hasn’t responded to a ping if one second
elapses without a response to the ping. In networks where ping packets have a low
priority, you may need to set the allowed response time to a longer time period. To change
this, use the command:

Polling frequency

By default, a polling instance polls a reachable device every 30 seconds. You can change
this by using the command:

Once the polling instance has determined that a ping has failed, it starts polling the device
at the frequency set as the critical interval—by default, one second. To change the
frequency set by the critical interval, use the command:

The critical interval enables the polling instance to quickly observe changes in the state of
the device, and should be set to a much lower value than the normal interval.

Configuring when

the device’s status

changes

The number of pings that the polling instance examines to consider a change in state is
controlled by the interaction of the

sample-size

,

fail-count

, and

up-count

commands. See

“How Ping Polling Works” on page 78.2

for an example showing this interaction.

To determine whether a device is reachable, the polling instance counts the number of
failed pings within a sample of a set size. The sample size is 5 pings by default. To change
the sample size, use the command:

To change the number of failed pings that the sample must have, use the command:

If the sample size and fail count are the same, the unanswered pings must be consecutive.
If the sample size is greater than the fail count, a device that does not always reply to pings
may be declared unreachable.

awplus(config-ping-poll)#

length <4-1500>

awplus(config-ping-poll)#

timeout <1-30>

awplus(config-ping-poll)#

normal-interval <1-65536>

awplus(config-ping-poll)#

critical-interval <1-65536>

awplus(config-ping-poll)#

sample-size <1-100>

awplus(config-ping-poll)#

fail-count <1-100>