This site can’t be reached - localhost refused to connect.

I'm trying to connect to my Cyber Power UPS web based management software (PPBE) but keep receiving:

This site can’t be reached localhost refused to connect.

Search Google for localhost 3052 agent

ERR_CONNECTION_REFUSED

I get the same error in Chrome, Edge and Firefox. I can't think of anything that's changed on my network to cause this. Can anyone help? It seems like a port issue but I haven't found a definitive solution.

Kol12 said:

I get the same error in Chrome, Edge and Firefox. I can't think of anything that's changed on my network to cause this. Can anyone help? It seems like a port issue but I haven't found a definitive solution.

Reading the Manual from here...

Troubleshooting Communication Problems
If Client is unable to communicate with the power devices, the following steps can help users troubleshoot the issue:

• Verify the network address is correct.
• Verify the network configuration for the UPS or PDU is correct. The Power Device Network Utility tool can be used to configure the network configuration. The tool can be installed from the tools folder on the installation CD or downloaded from CyberPower Systems | UPS Battery Backup, Surge, PDU - Power Solutions.
• Verify that the settings in the Security/Authentication page are correct and match the settings of the device. See Security/Authentication for more details.
• Verify the port in the Security/Network page is matched with the settings for PowerPanel Business Edition Agent.
• Check that the network status of computer and devices.
• Verify firewall settings. Port 3052(UDP/TCP), port 53568(TCP), port 161(UDP), port 162(UDP) and port 53566(UDP) should be unblocked. The computer communicates with the power device on these ports. The PowerPanel software installer will automatically configure the Windows firewall to allow PowerPanel® Applications access.
• Verify that the SSL certificate from the Client has been added into the trust list of Agent. If the Client applies a new SSL certificate and is not in the trust list, communication will be lost.

The last two items that I've marked in bold would seem the most likely causes.

Thanks Bree.

Firewall is not my strong point but I will try to find out if said ports are blocked for some reason. I'm not sure I can access an Agent trust list without being able to access Agent itself so it's likely the first one that's the problem...

Anolin said:

Go to C:\Windows\System32\drivers\etc and open your hosts and lmhosts.sam files with notepad and copy/paste the contents here. Just wanna make sure they don't have any weird entries.

Well my hosts file is actually filled with a coin blocker list provided here at Ten forums: Protecting yourself from In-Browser Miners Solved - Windows 10 Forums

I've attached copies of both my hosts and Imhosts.sam files.Hosts copy.txtImhosts.sam copy.txt

Samuria said:

Try using 127.0.0.1 instead of localhost its the same thing

Like http://127.0.0.1:3052/agent/ instead of http://localhost:3052/agent/?

Still same error: 127.0.0.1 refused to connect.

Samuria said:

Can you reach it from another PC by IP it's it http or HTTPS?

I tried accessing it on my phone in Firefox and it can't connect either. This then should be an issue with my router or an issue on CyberPower's software/server end?

Hi there
@Kol12

try first disconnecting all firewalls and disabling any A/V software.
Ensure also any Network cards in your system are working properly -- i.e correct drivers etc.

I think in your example you also need to ensure port 3052 is open / reachable -- you'll have to set that in your router - logon to your router and check ports -- these in sensible router hardware are normally closed by default.
A firewall also probably blocks these too by default which is why when testing network stuff disable firewalls - after it's working then apply the required level of security.

you should be able to ping localhost and see something like this from command mode -- this is on a Linux server but it's identical to Windows where you'll see an identical screen to the one shown.



another get around is to install the Ms loop back adapter - this will ensure localhost works even with no physical external network(s) available.

Install Microsoft Loopback Adapter

It's an excellent testing tool

What is Microsoft Loopback Adapter and why do we need it ? - Andrei DANEASA

ensure also that you have network discovery turned on.

It's probably a firewall or A/V software problem - or a combination of both.

Note you won't be able to connect to localhost on any other devices - you have to be on the local machine itself.
To access from another device you'll need to connect to its IP address on the network / use client software if you are connecting to a server.

For multi-media though I'd install something like Kodi then simple file sharing works fine - plus Kodi plays almost every video / audio stream known to man including ripped DVD ISO's on remote devices. - Install KODI on the remote devices - it's the client end and will pick up your multi-media on your server -- works fine on android phones, amazon fire TV boxes and hence remote TV's - even "Non smart" older ones.

cheers
jimbo