Right, so:

---
jim@jim-lappy:~$ sudo tcpdump -s 0 -w file.pca host 10.0.1.4
[sudo] password for jim:
tcpdump: WARNING: eth0: no IPv4 address assigned
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535
bytes
^C0 packets captured
0 packets received by filter
0 packets dropped by kernel
jim@jim-lappy:~$
---

This comes closer, but...it's still listening on "eth0".

How do I point it to wlan0?

Jim