Close open Tcp/Udp ports

Posted on 2005-05-08
Medium Priority
Last Modified: 2010-04-12
hi Experts,
How can i block my udp ports on win2kAs without any firewall or third party programs?

Question by:gomrok
LVL 31

Expert Comment

by:Wayne Barron
ID: 13954508
Good luck, I am not aware of a way to close these ports without using a Firewall
Either Software or Hardware (I prefer Hardware)

Linksys & Cisco Routers are the best.
Linksys - Low-Level Router "Low Cost and Maintance"
Cisco - Higher End Router "Better have a big Bank Account"

Good Luck
LVL 14

Accepted Solution

spiderfix earned 200 total points
ID: 13954978

Expert Comment

by:Leandro Iacono
ID: 13955205
Actually I have heard of a program that might do what you need. It was called something like "fport" but I am not sure if it was actually that name.

The point here, that everyone will eventually concure in pointing out is that the only way to "close" ports is by using them. What a firewall does, as I see it, is use up all ports on a computer. When a program needs a port, the firewall releases the port, and the program can start using it.

The point I am trying to make is that I am not sure there is a specific program in the microsoft OS that can "close" the ports, becuase thats not microsofts intention.

You will end up using a thrid party utility for these type of needs...
LVL 31

Assisted Solution

by:Wayne Barron
Wayne Barron earned 120 total points
ID: 13955443
Using a Firewall (Software Based)
Everytime that a program tries to use a Port, the Software will
Alert you that the program is trying to access either "in" or "out"
Of your computer through a port #.

To where using a Hardware Firewall, you have to set the ports in it.
Default ports are already opened.
Port : 80, 21, 25, 110

But for other ports, you will have to assign them physically themselves.
Like the "Cisco PIX 510"

We run the following Servers.
Web - Port 80
FTP - Port 81
Mail Server - Ports 25 & 110
Media Server - Ports ? & ? (Cannot remember there ports right now)

No other ports are opened, which means that nothing can get in through
any ports that are not assigned to be used.

Some program will tell you to open up
Ports - 2156 - 2200
Never ever do this.
That means that the program will use one of the ports from that range.
And the other ports will not be used except when it needs them.
BUT (this is the kicker that these idiot programmers do not think about)
The rest of the ports that you have opened, leave your system wide open
To any and all to come right on in and do as they wish.

I do not know of a program that will close the ports.

The information that [spiderfix] looks like it will be useful information,
But I would still strongly consider the purchase of a Router/Firewall (Hardware based system)

Linksys BEFSR41
Is the system that we used for about 2yrs before upgrading to a "Cisco".
But it is not as secure as it needs to be, there is still ports that are opened.
As a friend of mine found out.
But having a "Cisco" system inline, you have total control over everything,
And nothing left behind.

Good Luck
LVL 20

Assisted Solution

nedvis earned 80 total points
ID: 13964647
AnalogX has a really good and small  PortBlocker :
download it here: http://www.analogx.com/contents/download/network/pblock.htm

good luck

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