My N9 seems to have problems with the WIFI connection at work. I get a HUGE battery drain when connected to WIFI (always 300mA, Idle and Active). The WIFI connection is actually good and fast (Conky shows connection strength of 80%). The phone also gets hot.
Now I enable PSM or disable internet to get through the day at work.

At any other WIFI location I get a normal battery consumption and the phone stays cool.

Can somebody help me with Terminal commands to find the cause of the WIFI battery drain?
It's not related to my accounts because I also have the problem when all accounts are disabled.

Use top command in terminal to see which processes are using the most CPU usage and try to identify which one is astray. The use #kill and the process is to end it
Eg #kill 1102

I'll try the top command tomorrow at work. I already used Conky to check the top CPU% and nothing uses excessive CPU power.

you might also want to try powertop and Energy Profiler from the Power Analysis section of developer mode. Be sure to check the level of network traffic when the phone is idle. Sounds like a large amount of (broadcast?) traffic is waking the CPU from deep sleep

The "top" command shows no processes that use much CPU%.
I'll try the energy profiler. I'll let you know how it went.

Update
So I ran the Energy Profiler and this is what i noticed:
I constantly have some small "transmission in rate" (0,5 kB/s), I receive 3.1 packets/second.
Is this normal? I'm offline on my chat accounts.
Is there any way to see what kind of packets I'm receiving?

At home I get 0.2 packets/s and a Transmission in rate of 0.1 kB/s.
I guess the big amount of packets kills my battery and heats up my device, but why does Meego react to these packets? I have no problems with Windows Phone or Android at work.

icecream: no sweat, we'll get this figured out.

install tcpdump (in the stock harmattan repos) and run (as root) /usr/sbin/tcpdump -i wlan0

This will show you what network traffic the phone is seeing.

You can also try running
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all
This probably won't make a difference but whatever (setting only lasts until next reboot)

Finally, if there's no suspicious network traffic perhaps it's a problem with the wireless access point. Are there multiple APs at your work? Maybe you could test on a different one (different model would be best) It could be that the AP's firmware isn't letting the N9 idle correctly.

it could be as simple as some client mercilessly pinging everyone else...seen that with infected xp machines before. Usually IT tracks them down as it tends to slow the whole network.

@fignew: thanks for the info, I'll try it next week at work. It works here at home, I guess I'll quickly see what going on.

I constantly receive BROADCAST packets from pretty much every computer on our network. Is there a way to filter/ignore these BROADCAST messages?

A little more information:
allmost all messages are of type:
netbios-ns (port 137)
or
netbios-dgm (port 138)

Can somebody help me close these ports?