UVNC - blocking specific IPs oder hostnames


running the current CIS version I wonder how/where to define IPs that are allowed to connect to a local running UVNC server listening on port 5900?

I defined a global firewall rule in CIS like following:

Action: block
Protocol: TCP/UDP
Direction: In

Sourceaddress: Hostname
Hostname: vodafone-ip.de

Since I only want to allow IPs from Vodafone Pool I wonder why it does not work?

I would like to test parts of IP numbers too like for instance only allowing Vodafone-IPs beginning with:

But where can I definde such PARTS of IP numbers?

Thanks and best regards

First you need to change the action from block to allow then you can create a new network zone called vodafone and add each ipv4 address with subnet mask to the zone by clicking add new address and choosing type IPv4 Subnet Mask. Based on the starting ip address you listed I was able to determine the prefixes for vodafone that belong to AS3209 which list many other IP address prefixes for vodafone. See attached screenshot on how it should look like when setting up the network zone and firewall rule and make sure you make the same rule for the UVNC server executable under application rules. Also when looking at network prefixes that are in CIDR notation and you want to convert it to a subnet mask you can use this table CIDR Conversion Table for example would translate to IP: subnet mask: when you add the address to the network zone in CIS.

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