Hello,

If you happen to work at a work place blocking ports.

What ports are blocked? and What are ublocked?

For Example: My Uni allows on 80,8080.

I would like to find the most common port other then port 80, among the work places.

Regards & Thank you for any help.
EG

Incoming or outgoing ports??

Uh.. I'm not sure, its a little survey i'm doing. (part of assignment).

A few examples i can offer are.

- VNC Blocked (Port 5900)
- SSH (22)
- Flash Media Server (1935)

So, I'm not sure would they be incoming or outgoing ports..?

They are all "listening" ports therefore Incoming.

Blocking "well known" incoming ports is a security measure and many network managers would block ALL incoming ports with only the necessary ones opened.

1863 (MSN Messenger listen port) is another common port to be blocked.

Ok i get that.

A work place would usually have

80
81
8080

Most workplaces would not block those ports as port 80 is HTTP and maybe required by company employees.

What is done normally would be to route outbound port 80 (HTTP) and 443 (HTTPS) through a proxy server to allow monitoring and blocking of certain URLs.

Universities and colleges often block inbound port80, 8080 & 81 to stop students running unauthorised webservers or peer to peer networking on college machines.

Id say port 53 is the most used port at our place next to 80 and 443.

We dont really allow much else in our out.

Port 22 out is allowed, Inbound however its not ( along with most others )