4028 is the default port cgminer uses, so I believe all 6 of your AntMiners are using that port by default.

If you SSH into your AntMiner (if you're not familiar you can find a guide here), and change to the /etc/config directory and type "vim cgminer" (without quotes) and press Enter, you'll open the miner's config file settings. It isn't in the format of a normal cgminer config file, so I don't know that all config settings work here (I think BitMain tried to dummy-proof the config), but if you don't see an "option api_port" listed, the miner should be defaulting to 4028 (unless BitMain is setting this to something different outside of this config file). I'm guessing the AntMiner reads in this config file then launches the miner using these settings as command-line arguments along with "hard-coded" settings.

While in this config file, it is necessary to include CGRemote's IP address in the "option api_allow" setting, along with 127.0.0.1 (which is the AntMiner's IP so its web interface can access cgminer). For example, the setting to allow access to the miner for the AntMiner itself and from any computers on the local network would be:

option api_allow 'W:127.0.0.1,W:192.168.1.0/24'

I purchased an AntMiner just to make sure CGRemote worked correctly with it, but so far I haven't had any issues. I do not have api_port listed in my config, and I had no problem connecting CGRemote to it using port 4028. From what I understand, you should be able to connect to all six of them by setting them up in CGRemote using their individual IP addresses along with 4028 as the port.

I have started on an auto-detect feature for detecting miners on the local network automatically... but we're working on a lot of things right now so I don't have an ETA yet.