I have some linksys DOCSIS 3.something box here. All is naiss except I can only log into it once I do a hard reset and not screw in the cable.
If the cable is in the box will get locked and I will no longer be able to get in. Good thing is all my settings are retained but it is still a huge PITA if I have to change something, I would have to re-enter all old stuff aswell as the new things. Sometimes there's a firmware update or such and all my settings will be lost (and my server will go invisible lol).

My friend was just given a new modem by Comcast, which I believe is an Arris TG862. http://www.arrisi.com/products/product.asp?id=79 I never liked cable modems with built-in Wi-Fi/routing capabilities because of the lack of the ability to install DD-WRT, poorer reception (no external antenna(s), and the fact that if one or more components fails which drives one of the three functions you're left with a partially working half-brick. Do you really want to waste your time troubleshooting a chinese clusterfuck orgy in a box? I certainly don't!, especially when routers are cheap!

And get this, and here's the kicker. You have to call Comcast to ask them for their permission to have them put your modem into bridge mode which is necessary if you use an external router (you could do DMZ but this is wrong)! Not only that, but there are stories all over the internet about people asking Comcast to do this and they don't know what the fuck the customer is talking about. I don't know if this is Comcast's fault or the fault of Arris, but taking that kind of control out of the customer's hands who may be an I.T. person/programmer is fucking ridiculous!