Are you receiving a Webmin unable to connect error?

Webmin connection errors happen due to service failures, lack of server memory, firewall restrictions, etc.

Managing users and domains becomes tough when the Webmin panel is not working.

Here at Bobcares, we routinely resolve Webmin errors as part of our Server Management Services.

Let’s see the possible causes and how we fixed Webmin access for one of our customers.

How does Webmin unable to connect error appear?

Recently, one of our customers came with the request.

I cannot access the control panel at https://xxx.server.com:10000

The browser gives the error: “site refuses to connect”

I tried Webmin restart command and it did not work. Please fix it.

What causes Webmin unable to connect error

We’ll now take a look at the top causes that can make Webmin unavailable.

1. Webmin service unavailable

One of the primary reasons for Webmin’s connection errors can be service unavailability. The webmin service status can be checked using the command:

service webmin status

If for some reason there are errors, it will cause Webmin to fail. Thus it will not accept connections on port 10000. As a result, the user experiences error in the browser too.

2. Firewall restrictions

In many new Webmin installations, the firewall restrictions create trouble with Webmin access.

By default, Webmin runs on port 10000. Therefore, we have to open connections to this port in the server firewall. There should not be any port filtering on the computer from which the user tries to access Webmin.

Here, our Support Engineers easily finds out the status of Webmin port by executing

netstat -lpan | grep :10000

3. Insufficient server resources

Lastly, Webmin unable to connect error can even happen when there are limited resources on the server.

For instance, when a customer reported problems with Webmin, the server had no free memory. Moreover, the logs showed these entries too.

May 07 19:41:29 srv02 webmin[24953]: Stopping Webmin server in /usr/share/webmin
May 07 19:41:29 srv02 webmin[24953]: /etc/webmin/stop: 4: kill: No such process

Here, the clamscan process was consuming too much memory. Thus the low free memory caused problems with Webmin.

Fixes for Webmin unable to connect error

Now that we know why the Webmin error occurs, let’s check the fixes too.

When the customer approached with Webmin unable to connect error, our Webmin Engineers first checked for the status of Webmin service and port 10000.

Here, the webmin was not working properly.  Therefore, we restarted the service using:

service webmin restart

Further, we confirmed the status of Webmin port 10000. The successful results appeared as

root@srv02:~# netstat -tpln | grep 10000
tcp 0 0 0.0.0.0:10000 0.0.0.0:* LISTEN 24965/perl
tcp6 0 0 :::10000 :::* LISTEN 24965/perl

root@srv02:~# service webmin status
● webmin.service - LSB: web-based administration interface for Unix systems
Loaded: loaded (/etc/init.d/webmin; generated)
Active: active (running) since Thu 2020-05-07 19:41:32 UTC; 32s ago

In cases where the port does not listen correctly, we open port 10000 in the server firewall using these commands.

On an Ubuntu server with UFW firewall, we execute

sudo ufw allow 10000/tcp

Similarly, to open port 10000 in iptables, we use

iptables -A INPUT -p tcp -d 0/0 -s 0/0 --dport 10000 -j ACCEPT

Also when the server has memory constraints, we try to free up some memory on the server. Or, we add additional memory on to the server too.

[Trouble in making Webmin panel work? Get help from the experts.]

Conclusion

In short, Webmin unable to connect error happens when there are problems with Webmin service, firewall restrictions, or even due to insufficient server resources. In this write-up, we saw how our Support Engineers made Webmin working for one of our customers.