Setting The Source Address For Probe Packets; Setting The Source Port For Probe Packets - HP 7102dl - ProCurve Secure Router Configuration Manual

Network Monitoring
Configuring Network Monitoring
Of course, you may not want to decrease the period too much, because probes
add overhead to your network. Also, when you are testing for connectivity,
you should set the tolerance for ICMP echo probes to at least 3 in order to
compensate for routinely lost packets.

Setting the Source Address for Probe Packets

By default, the probe takes as its source the address of the interface through
which it was transmitted. Leaving this setting at its default is often a good idea
because the probe requires a valid address on one of the router's local
interfaces in order to function properly. When you manually specify a probe's
source address, you risk a probe malfunction if the local interface address is
changed later.
To set the source address for probe packets, from the network monitor probe
configuration mode context, enter:
Syntax: source-address <A.B.C.D>

Setting the Source Port for Probe Packets

For TCP connect and HTTP request packets, you can also specify the source
port. By default, the router starts sending probe packets out from port 1026
and increments by one with each probe packet. But you can override this
behavior and configure the probe to send packets from a set port.
From the network monitor probe configuration mode context, enter:
Syntax: source-port <number>
Valid ports range from 1 to 65535.
Consider whether a firewall stands between your router and the remote server
that it is testing. If it filters out certain source ports, you should change the
probe to an acceptable port. Also consider allowed source ports in ACLs
configured on other network devices.
Another reason that you might set the source port manually is to distinguish
one probe's traffic from another probe's, even when the probes have the same
destination. Thus you can configure a route map entry to forward one probe's
packets out a primary interface, and you can configure another route map
entry to forward a second probe's packets out a backup interface.
9-17