Thanks, I have installed WireShark. However, when I ran it, no interfaces were showing. Possibly it has to be run as "sudo" to get the interfaces ??
Anyway, read a bit on their site, and came across a utility called dumpcap, which is already installed under Kubuntu. Used one of their examples ..
and then browsed the XP share whilst that was running. Then opened that file under WireShark. There were lots of entries, but none for that BigPond IP address. So, I'm thinking that I have the wrong interface ??
$ sudo dumpcap -i eth0 -a duration:60 -w Documents/output.pcap