How can I block all incoming UDP ports

[Bulent Tekcan]

Hello,

My server has a 7 domain...But I need only block all incoming udp ports to 1 domain IP. I'm using CSF firewall, how can I do that ?

Regards,
Bulent

 

[cPRex]

Hey there! If you wanted to block all UDP traffic, you would change the UDP_IN and UDP_OUT sections to have no IPs, so they would look like this:

# Allow incoming UDP ports
UDP_IN = ""

This would keep DNS from working on the machine.

Firewalls are not domain-based, so there isn't a way to stop that type of traffic for just one domain. This would affect the entire server.

Since network connections are typically pointed at an IP address, I wouldn't expect there to be a need to filter UDP traffic based on a domain, as there isn't a service that's listening for domain-based connections based on UDP.

 

[Bulent Tekcan]

Hello,

I found a way, and working perfectly. Put in csf.deny

udp|in|d=1024_65535|d=xxx.xxx.xxx.xxx

Now blocked all incoming UDP ports.


Regards,