I use either of two methods depending on the situation.
- If I'm doing iperf active survey with AirMagnet, I carry a second laptop as a server and plug it directly into the AP. works great, no switch required.
- carry a cheap little 5 port ethernet switch and plug that in with a very short jumper.
We are aware this is less than ideal if you're just doing passive surveys - although we don't recommend just passive surveys as they don't tell you much about how actual traffic is going to pass. Instant used to require a DHCP server plus uplink. It is now just uplink.