So that tells us that the problem lies in one or more of the firewalls between client pc and zoo server pc. Starting with the zoo pc firewall and on the zoo pc:
Click on Search in the taskbar and type defender. You should see Windows Defender Firewall with Advanced Security - click on Run as Administrator and you should get to a window like this:
If there is a message that another Firewall is managing security then you will have to translate the following steps to that firewall’s manager app.
Note which of the three profiles shown is active.
Click on Inbound Rules in the left column. You will get a list of the rules set up. There are lots of columns so it helps to widen the window as much as possible.
Look for the rule that Dale suggested, named ‘Zoo TCP Port 80’. The rules will probably not be in alphabetical order but you can sort them by clicking on the heading ‘Name’.
The rule must:
- have a Green tick
- apply to ‘All’ profiles or the active profile
- show Action ‘Allow’
- reference Local Port ‘80’
Do the same for the Outbound Rules.
If you don’t have both rules, and both meeting the criteria, run Dale’s script again and recheck.
If the rules are correct, we need to check for conflicting rules. Sort the list by Local Port and look for other rules related to Local Port 80 and Protocol TCP. For each one, look for Action set to ‘Block’ and see if they apply to your active profile (or All) and have a green tick. If you find any you will need to work out why that rule is there and whether it is safe to disable it.
If you have Dale’s rules and no conflicting blocks, this firewall is not the problem: time to try the client PC. If that is also clean you need to consider whether there are any intermediate firewalls, or network infrastructure like switches or routers, which could have port blocking capabilities. You’ll need to involve your IT guys at that point…
Unfortunately you also need to make this check for a port block for any range of ports encompassing port 80 (for example 68-500), which is tedious to do.