Selective offline mode -- IP based whitelisting

As well as developing plugins, I also work on client mods. Using MCP and debugging code, there is no way to authenticate yourself -- MCP assigns you a username and works in offline mode. This leads me having to resort to cracked servers so I can properly test my client mods.

I have a static IP (let's say it's 172.16.254.1). Is there a way for my server to remain in online mode, but for me to whitelist 172.16.254.1 and allow users to connect from that IP without having to be verified with the Minecraft session server?

I'm unsure as to whether a plugin would be able to do this, which is why I am asking here.

 

You can check the ip and block all connections but that ip, though if you need to test just run a local only (non port forwarded) server.

 

The issue is I want to test capes etc (on other users). That would require more than one user online.

 

You can use something as such as an IP whitelist, let me find one for you.

http://dev.bukkit.org/server-mods/ipsecurity/