asked on

Ports to block security

hey guys,

i have a cloud server, and i'm looking for a list of essential ports to block to keep it safe. This wont be anything production so its not a big deal, but looking for a basic list.

Thanks

serialband

What does your server do? You're going about it backwards. The standard practice is to block everything except the ports you want running.

If you're running a web server, you'd leave port 80 and port 443 or just port 443 open. You probably want to RDP to it, so you should open a port for RDP, although I suggest not using the standard port, unless you only allow certain known, fixed IPs through.

Bill H

ASKER

ok, im looking for standard ports to block please thats all.

serialband

Block ports 137, 138, 139, and 445

It's still better to block everything and whitelist the ones you want. It prevents random software from opening ports on you without your knowledge.

Bill H

ASKER

thanks serial! what ports does SQL use? any other ports? are those all TCP or UDP?

Kind of doing an experiment here.

serialband

They're a mix.

UDP on 138
TCP on 139
both on 137 & 445

SQL on 1433, and client ports are assigned a random value between 1024 and 5000.

Bill H

ASKER

I thought SQL used more than 1 port.

Client ports I'm not concerned with

ASKER CERTIFIED SOLUTION

Monika Bharti

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

serialband

You're right. I found the SQL port information from this site
https://msdn.microsoft.com/en-us/library/cc646023.aspx

UDP port 1434
TCP port 1433
TCP port 433
TCP port 4022
TCP port 135

@Monika If you're going to cut and paste full text someone else's information from what appears to be some college website, please at least link to it and quote it. They deserve some credit.

Bill H

ASKER

Thanks guys!

Any others were missing?