Mudkip
The Mudkip
can get banned but most likely not
No you cant, because Bungie can not BAN people.
What you can get is RESET that means you lose all your credits, all your armor, and your rank.
You keep your commendations (thats to make it harder for you to boost as you gain less Cr the higher your commendations)
Also you will get credit locked for a period of time, that means that you cannot gain Credits for a while. (TEMPORARY!)
But you CANNOT GET BANNED!!!! (banned meaning not allowed to play Halo Reach online anymore)
Any type of Network manipulation (unconecting cord, signing with an offline profile to confuse the system, putting your modem on standby etc etc CAN alert bungie and they can reset you)
If you replay Checkpoints, or Play some type of game a lot you WILL NOT GET RESET OR BANNED.
Hope this clear it out for you.
I've capped out my online credits 5 times, never been banned though.
by doing the ethernet glitch?