Errors while connecting to IRC

Question

Connecting to chat.Freenode.net:

Using normal ports, properly forwarded and firewall allowed.

Problems/Various situations:

1. Connects, shows MOTD, mode +i on me, Nickserv tells me to identify. I also get a [frigg VERSION]. No response whatsoever after connecting, but it doesn't DC me either.
2. Connects the same way as (1). Doesn't respond when I identify myself for example. Finally disconnect's me after about 1 minute with [10053] Software caused connection abort
3. Connects and you seem to be able to send messages and receive them. You try to identify yourself and you get dentify Unknown command or RV Unknown command and usually when you send it again it works. You can also get DE Unknown command and some others I can't remember when joining a channel. Despite the unknown commands, this situation is the only one that usually let's me interact with the server and stay online and may or may not drop after I start talking.

Why does mIRC just does not work correctly nowadays?

Answer 1

Look at the IRC server's MOTD. The IRC server might be using another IP trying to check if you are an open proxy; if you have this IP blocked the server will think you are trying to evade the scan and it will drop you.

Alternatively it might be dropping you because your client isn't responding to /ctcp VERSION requests or something like that. Read the MOTD to see what it's checking for exactly and how.