Administrator's Guide

Chapter 12. Tools
Under Tools, you find handy tools to troubleshoot the Telecommuting Module setup.
Packet Capture
3Com VCX IP Telecommuting Module has a built-in packet capturer which can produce
pcap trace files. This sniffer will capture all IP packets according to your selections, even
those you can’t see in the log (like RTP packets).
The Telecommuting Module capturer needs to be manually activated and deactivated. As
this produces a log which usually contains a lot more packets than the standard log, it is
advisable only to run the capturer for short time periods.
The capture of the packets can be downloaded and analyzed in any tool that handles pcap
traces, like Ethereal/Wireshark.
Network Interface Selection
Select on which interface or VLAN the sniffer should listen for packets. You can also select
to listen on all interfaces.
Some network cards have VLAN hardware support. For this type of cards, incoming VLAN
tagged traffic is not logged on the main interface, but only on the VLAN interface. Outgoing
VLAN tagged traffic is logged on the main interface.
Other interfaces do not have VLAN hardware support. For this type of interface, VLAN
traffic is logged on the main interface.
Currently, the only network cards in 3Com products to support VLAN are the Gigabit net-
work cards.
IP Address Selection
You can limit the selection by specifying certain IP addresses.
In these fields, enter a single IP address (e. g., 10.3.27.3), a range of IP addresses (e. g.,
10.3.27.1-10.3.28.254), an IP address followed by a netmask (e. g.,10.3.27.0/24), a combi-
nation of these, or nothing at all. If a field is empty, all IP addresses are selected.
If you want to study all traffic except the one to or from a specific computer or group of
computers, enter the IP address(es) here and mark the "not this address" box.
The selection can be modified by the control boxes under the fields A and B:
A src Packets from the IP address in field A matches. Field B is ignored.
A dst Packets to the IP address in field A matches. Field B is ignored.
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