Unable to connect from the Internet after update

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donfano
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Unable to connect from the Internet after update

Post by donfano » Tue Mar 08, 2011 2:18 pm

I need help to figure out why I can no longer connect to Cerberus from the Internet.

Cerberus has been running fine, and I have recently updated it with 4.0.8.3. I believe the version I had was 4.0.8.2. I know, I know... "don't fix it if it's not broken" :oops:

Actually, it is not true that no connections could not be made from the Internet since the update. I have noticed some logs of hackers who are trying to connect with id's, such as Administrator or Mysql. Since I turned on the auto-blocking option, their IP addresses have been blocked. So why were they able to connect, and not anyone else with valid id's? :?

Here are additional details:
+ Cerberus 4.0.8.3 installed on 64-bit Windows 7
+ Cerberus is added to exception list (Profile: Private and Public)
+ I can connect to Cerberus through LAN using the Win7's local IP address, i.e. 192.168.x.x
+ I can ping to either my external IP address or DNS
+ Port forwarding is enabled from the router
+ Port 21 is opened successfully from http://www.canyouseeme.org/

When the user tries to connect to Cerberus from the Internet, the user gets "Connected to <DNSname>" followed by "Connection closed by remote host". However, Cerberus does not report any connection attempts.

Any help would be greatly appreciated!

Regards,

--DonFano

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Serin
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Re: Unable to connect from the Internet after update

Post by Serin » Tue Mar 08, 2011 2:52 pm

My first guess would be that if the Cerberus log reports nothing at all, Cerberus is not the process being connected to. Could there be another process now listening on port 21? What happens if you stop the server and then try to connect? Does the client connection behavior change?


Any chance your firewall is interfering now? Perhaps it needs to be checked since the Cerberus.exe changed... that shouldn't be necessary but you never know.

donfano
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Joined: Tue Mar 08, 2011 1:17 pm

Re: Unable to connect from the Internet after update

Post by donfano » Wed Mar 09, 2011 9:17 am

I ran the following command to determine which IP/Port is being used by a given program:

Code: Select all

NETSTAT -p tcp -ano
and I did not see any reference of port 21 in the output

I stopped the server, and the client behavior does not change. This is true if I am using the command line. However, the FTP client does report that it was unable to make a connection.

Although I disabled the port forwarding from my router, the FTP command still reports that it was "connected" and prompts for the user id. Is that normal?

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Serin
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Re: Unable to connect from the Internet after update

Post by Serin » Wed Mar 09, 2011 10:39 am

Have you tried connecting externally by using the public IP instead of the dynamic DNS name?

donfano
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Re: Unable to connect from the Internet after update

Post by donfano » Thu Mar 10, 2011 3:21 pm

I think I somehow resolved the problem. :D

I thought of doing a repair for Cerberus install, but I was surprised to see two entries for Cerberus in "Programs and Features". One was "Cerberus FTP Server" and the other was "Cerberus FTP Server 4" (if I remember well). Instead of performing a repair, I simply removed the two entries and planned to reinstall from scratch. When I went to the Cerberus site, both 32-bit and 64-bit versions of the server are available for download. I came to realize that I had a 32-bit version installed before since the server was installed in "Program Files (x86)". I downloaded and installed the 64-bit version server, and now everything is working fine.

Just thought you should know and thanks for your assistance! :)

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