What Can Be Preventing Port Opening?

By abrogard ·
I cannot port forward to one computer on my LAN. But I can to any other.

It runs win10 and IIS. The IP is static, both the web IP and the local IP.

As I say, forwarding to another computer on the lan also running IIS works fine. So looks like the router is fine.

And this computer used to work fine, too.

I have reinstalled win10 using that web based MS 'upgrade' method that leaves your apps and files intact.

It has not helped.

Telstra (the ISP) techies spent 4 hours here and they couldn't crack it.

Opera claims the site 'refused' to connect, if that's any sort of clue.

All web interaction on that computer works fine (i.e. now, doing this).

Web based port checkers report all ports closed - even port 80.

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by sjvn Tech expert In reply to What Can Be Preventing Po ...

I presume you tried the obvious: Turning off the firewall:

to see if it's a firewall permissions problem?

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all interfaces

by abrogard In reply to Ports

sorry, should have mentioned that. yes, I tried with all firewalls down.

eventually I fixed it with netsh http add_listen ipaddress =

followed by iisreset.

after first doing a 'show iplisten' and seeing it was required.

So it would appear that despite all configurations to IIS being apparently as they should be - i.e. every 'normal' step being followed and every configuration advice from IIS pros being followed - that IIS can still fail to be listening where it should be.

And ports appear closed if there's nothing listening to them.

So I guess technically that'd be the answer to the question I put: "Many things including nothing listening"

And a first step fix: look to see what's listening.
And what should be listening?

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