Everything was working fine, but when I restart the server I cann´t enter to the administration of virtialmin, if I put the Internet address of the server with no port shows me the information of Apache or info.php but if I put the address with specified port not charge me anything.
Normally, you’d be able to access Webmin/Virtualmin on port 10000.
If that’s not working, you may want to verify that the Webmin process is running. You can do that by logging into your server over SSH, and running this command as root:
/etc/init.d/webmin restart
After that, try accessing port 10000 again – does that work correctly?
-Eric
the default port I was changed about 6 months ago, and the webmin process is running on server, I use /etc/init.d/webmin restart but still not work
Does restarting Webmin complete successfully, or do you receive an error message?
Also, when trying to access Webmin via your browser, what error do you get when you try?
-Eric
my browser only display “Cannot display the webpage”
ahhh and webmin restarts normaly, stoping / starting… without error messages
I’ve seen that error for various websites on IE in the past – and also noticed that using a different browser seemed to resolve it 
Are you by chance using IE?
And if so, what if you try something like Firefox… are you by chance able to access Virtualmin?
-Eric
I use both browers, firefox by default and some cases IE, but I can not access to virtualmin with any of both
(Sorry for the late reply, have been trying to post this for the past two hours, but the server is very slow again, up to multiple “500” errors and failures to respond.)
To rule out possible further reasons why connection fails, you can do the following tests, on the machine where you try to connect from:
ping IP
dig HOSTNAME
telnet HOSTNAME PORT
where IP and HOSTNAME are the IP address respectively the hostname of the vmin server, and PORT the port number on which it runs.
On the vmin server, you can do:
ifconfig
iptables -L
You might post the outputs of those commands here.