I have been learning networking recently through the CCNA course by danscourses and plenty of other study through books etc.

Throughout the course I have become accustomed to using Cisco command line interface through Packet Tracer though I know want to start experimenting with my D-Link home router so have to start learning new command line interface syntax. I was wondering aside from cisco and D-Link what other command line interfaces would I need to learn as I strive to become more proficient in networking or do these two companies cover most bases.

Thank you to all the guys who recommended me resources the last time I posted a thread.

Every supplier might have its own set of instructions and commands, maybe even every single product (line) (version) might have it. What is/is not supported, which commands can be used and which syntax applies can usually be found in the related documentation. If in doubt ask the supplier.

I found that many IP network routing equipment suppliers use kind of Cisco compatible command set, but if that's the case can only be found out by either trying or RTFM.
It like with cars: Usually the brake is always in the same place, but finding the fog light switch can be some kind of adventure.

Cisco really is the giant with networking devices, however, I disagree that D link cover mose 'bases' than Juniper does. (as far as enterprise networking is concerned).

There I've said it, do involve yourself with Juniper, it is a huge deal to Cisco since Juniper has been emerging as a huge competitor in the firewall market.

Good luck and enjoy your career with networking! I hope this post helps