How do I check if a port is blocked from the WAP/ISP/Hotspot I'm in?

cwwilson721 · 11-06-2006, 03:24 PM

I travel for a living (truckdriver). 99.9% of the places I get online I have no issues, however today, I found I can't login to Yahoo messenger. When I tried to ping, I got a "Packet Filtered" result.

So I know it's killing pings. How do I check the ports?

Quigi · 11-06-2006, 03:34 PM

Are you interested in specific ports? To try and connect to port P on host H,

Code:

telnet H P

You'll get "connected to H" or "connection refused", or it hangs forever. (If connected, you probably don't talk the righ protocol by hand, and you get disconnected soon.)

tobyl · 11-06-2006, 04:40 PM

If you know which port Yahoo messenger uses (5050 a quick google told me)
You can go to an online port scanner, eg

https://www.grc.com/x/ne.dll?bh0bkyd2

turn on your messenger client, then

hit proceed, type in the port or port range, and click the "user specified custom port probe" button

since you are not blocking it, if it is blocked, it must be upstream, (ie your isp)

if it is working ok you should get closed when the yahoo app is not running, and open when it is.

tobyl