Cable modem question (Comcast)

I just called Comcast to get the scoop on cable modems.

As I am an existing customer, I get the $43/mo rate. Add in the $12/mo for regular service, $3/mo for the leased modem, $10/mo for 3 extra IP addresses (why can't I use a router? I know the cable company can benignly or maliciously prevent 'unauthorized' computers, and the fact they want more money for addresses suggests a static IP connection. :puke: ) Plus unknown fees, I'd be paying at least $68/month. :wow:

I'd also have to buy a hardware firewall to take advantage of the features my DSL router has (that's $100 one-time purchase). But it's a firewall/router. Would Comcast see what I'm connecting to their modem and then shut me off?

Now they CLAIM that every user has their own line and dedicated speed (3mbps both ways), but I'm skeptical...

More importantly, they don't support Linux. If you have cable modem service via Comcast and use Linux, does it work? (the salesman had no clue, even when I went into specifics as to how Windows computers are configured... I was hoping for something simple along the lines of "Configuring the TCP/IP protocol"...)

Thanks!

but we've got a comcast cable modem at our place hooked up to a router and 3-4 computers, and they haven't had a problem with that...

extra computers or even "spoof" if you want to.
They shouldn't care about the firewall but would frown on the router. if you told them :)
...and Linux would work fine..

Just don't tell 'em about it. All they see from their end is one IP address. The router assigns the others internally, and all outgoing traffic funnels through the assigned external Comcast IP.

Just don't go hog-wild dl'ing mp3s all night from four computers at once....

Routers all have an internal hardware firewall, BTW. It can be configured any way you wish.

Linux works fine with Comcast. Just hook up the lan cable and boot up. No software needed. (I have a SuSe 9 machine-- I've also used Red Hat. Not a sign of trouble with any of 'em.)

If you need to configure TCP/IP just make it dynamic-- static IPs are a thing of the past. Dynamic is pretty much the default configuration on everything, unless specifically told otherwise.

so it looks like a PC to them.

...is the cable modem's address.

If they really want to spot routers they can look for high ports and IP IDs - no easy way to spoof those.

Google "linux cable modem" and "linux ethernet" for the appropriate HOWTO's. I'm on a Cox cable and it was a snap-- basically just let DHCP take over the details, as I recall. The only issue I had was that my motherboard has on-board 10/100 and gigabit ethernet support, and I didn't realize on the first attempt that eth0 defaulted to the gigabit port rather than the 10/100 connection to my cable modem.

;)

I already have it. However, I'm tied with a phone line to it.

As I have a cell phone and want to ditch the land line, I discovered that Qwest's only ala-carte DSL solution is a $49.95/mo option that gives me 1.5mbps upload/download capability.

So I could pay $60/mo for 256/256kbps and a land line, or 1.5/1.5 and no land phone.

and a few months ago we went down and I called tech support. He led me through the whole resetting thing with the router. he never said anything about it not being allowed.

Comcast only requires that you have DHCP enabled to acquire your IP address (unless you are assigned a static one). Simply enable your DHCP client on your Linux box and you're set to jet. At least, that's all I had to do get on the web the last time I had to connect my computer directly to their cable modem... Normally, I don't connect directly to their network, I have a wireless access point that does and it serves as a firewall and NAT router which dishes out its own set of IP address to systems on my local subnet.

buy a $60 Netgear Router and connect it between your computers and the cable modem. You can set up port forwarding to each of the networked computer, i.e setting IP as 196.255.0.1, 02, 03 etc...

Comcast used to sell a networking kit which was one router. You don't need to buy their stuff as they support every router in the market. as for the second IP address, I was using that service too, but they told me I didn't need it anymore.

Call customer service and ask them about IP addresses, I bet you only need one and each computer will automatically pull one from the DNS server.

As for security, routers with NAT and port forwarding offer pretty good protection. AND Comcast rotates IP addresses every couple of days so you won't always have the same one if you have a router running all the time.