By Hezron Chacha | October 30, 2017 | 2 Comment
I downloaded GNS3 and successfully installed the latest version (2.0.3) on my laptop that is running on Windows 7 Professional Service Pack 1 (64 bit). I got an error while trying to connect to the server “Error when connecting to the GNS3 server: Cannot connect to http://127.0.0.1:3080. Please check if GNS# is allowed in your antivirus and firewall. And that server version is 2.0.3.”
I tried to google a number of blogs to help me fix the error and finally got the fix. From my research, it appeared that this error happens when you first run GNS network simulator on a Windows as well as Linux operating system environment.
The simple fix before you check your anti-virus (McAfee 18.104.22.16893 as for my case) and firewall software, run GNS3 as an administrator and it works perfectly.
This fix works well to resolve the error “could not connect to 127.0.0.1 on port 800: [WinError 10061]No connection could be made because the target machine actively refused it.” This error occurs when you drag and drop some devices like router on the GNS3 network simulator. Read More on this article.
Photo credit: Technig