Cable Internet questions

Jesus Freak · Post by **Jesus Freak** » Sat Jan 01, 2005 11:06 am

As some of you may know, I have cable now(woo hoo!). Anyhow, I'm a newb, and need to be educated. I'm having some hardware problems right now. Here are my questions:

1. The cable dude who installed it in our house installed it on 1 pc. I try it in my other pc(5 feet away from it) and, although the modem says I'm on-line, my computer won't go on-line. It seems it can't find an IP address or some crap like that. I have LAN Settings set on "Automatically Detect Settings". Tried several times, no go. How do I get the computer to go on-line??! Which leads me to my 2nd question.

2. I want to use the cable in another room. Now the entire house is wired for cable, and I set it in our basement so that the cable is going to that room. The signal for TV is faint. The modem can't seem to receive anything, I'm guessing cause the signal is too weak. Well my Dad says we need an amplifier. We have a tv amplifier, but he says we need a Digital amplifier for Internet cause it's a different signal. That true? How much does one cost and where can we get one?

3. Anything else I aught to know as a n00b?

Thanks

Krom · Post by **Krom** » Sat Jan 01, 2005 11:31 am

Get a router.

To get the cable working on the other computer, you need to duplicate the TCP/IP settings. (network connections in XP, Network control panel anywhere else).

Amplifiers won't work, you have bad cables in your house, get better ones, better yet, get a router.

Jesus Freak · Post by **Jesus Freak** » Sat Jan 01, 2005 11:59 am

I have a router... 2 in fact. A Linksys BEFSR 81 and a netgear. I'd like to have wired cable to my room and wireless throughout the house. Problem is my room is one of the 2 spots in the house that gets a weak signal.

Cuda68-2 · Post by **Cuda68-2** » Sat Jan 01, 2005 12:32 pm

You need to clone the MAC address from the PC you originally had set up to the router. Just write it down and go into the setp up of the router and type it in. They use the MAC address in place of a login to identify you.

Boo · Post by **Boo** » Sat Jan 01, 2005 12:32 pm

I have a linksys wrt54g. Wireless, and it seems to have a nice signal, no blind spots. BTW, which OS are you running?

Testiculese · Post by **Testiculese** » Sat Jan 01, 2005 2:45 pm

How about putting the router and the modem in the (basement, or the room) where the cable comes in, and run a line to your room, wireless for every one else.

Krom · Post by **Krom** » Sat Jan 01, 2005 2:52 pm

He wants the cable modem in his room, and he also resists using the router because "BitTorrent doesn't work when I use the router". I sent him a link explaining how to use static IPs and port forwarding.

Matrix · Post by **Matrix** » Sat Jan 01, 2005 9:58 pm

Cuda68-2 wrote:You need to clone the MAC address from the PC you originally had set up to the router. Just write it down and go into the setp up of the router and type it in. They use the MAC address in place of a login to identify you.

The MAC address the ISP uses to identify a user is the MAC of the Modem, not the NIC
He would only want to clone his NIC MAC if he wanted to have the same IP address when he moved the modem to a different comp

The reason he couldnâ??t connect to the net when he put the modem on the 2nd computer was because he didn't release the IP before disconnecting the modem from the 1st computer. Most ISPs only allow u to obtain 1 IP at a time, when he connected the modem to the 2nd comp he was trying to get a 2nd IP before he released the 1st one.
If your using the router and u want to release ur IP u go to the config page (http://192.168.1.1/Status.htm) <--Linksys, and click "DHCP Release"
Then unplug the modem and move it to the next computer

Or w/o the router, go the cmd prompt and type (ipconfig /release *Con*)
Then unplug the modem and move it to the next computer

Also usly just shutting off the computer while the modem is powered up releases the IP

And like krom said, amplifiers do not work with cable modems
I think they do make some more expensive amplifiers that are for cable modems but all u are doing is amplifying a crapped up signal
If the modem doesnâ??t work in certain rooms its ether cuz ur lines are crapped up, or u are using too many splitters

Jesus Freak wrote:Problem is my room is one of the 2 spots in the house that gets a weak signal.

How many spliters are u using between the main line coming into ur basement to ur room? is the sheilding on the lines damaged at all? how old are the spliters?

JF, IM me and Iâ??ll help u setup static IPs on ur router and how to forward ports so BT will work

Capm · Post by **Capm** » Sat Jan 01, 2005 11:11 pm

Being a Cable Guy (Broadband Technician, actually) I have a few answers for you....

1) Leave the Modem where the tech put it! DO NOT try to use another outlet, it will not work. (Shouldn't.. anyway, if it was done right) In Cable modem installations, the modem outlet is isolated from the TV outlets by a High-Pass Filter. This blocks the return signal on all the outlets but the one the modem is hooked up to in order to prevent TV's from throwing trash back into the cable system and taking all the modems down.
From the Tap (where your drop hooks into the cable system) to your house, there should be a two-way splitter (or a Directional Coupler) with one leg going to the cable modem and the other leg should have the high-pass filter and then goto the rest of your outlets. That single two-way is ALL that should be between your modem and the tap. There should be NO SPLICES in the OUTLET or the DROP. NO CORROSION of ANY KIND. If your signal is so poor on your cable modem that you need a cable modem amp, then there are problems that the cable company needs to fix. You should not need a cable modem amp for ANY REASON. They do not effect your bandwidth, either, btw so if you thought you could hot-rod your modem, you're wasting money and probably causing a return path problem in the process by blasting the input of the first amplifier in the line.

Maybe I'll make up a little FAQ w/pictures or something when I get a digital camera, I can show you exactly what things SHOULD look like.

2) Most ISP's now only allow 1 CPE (thats like, your pc, or a router or other devices that take an IP) Which basicly means, you get 1 IP. This is half of the reason when you hooked up the other machine it didn't work. The other half is because that cable modem learns the MAC address of your NIC card, and since it is allowed only 1 CPE, then any others that hook up to it will be denied. SO.. what you need to do, is get the modem to dump that mac address. Usually, unplugging the modem for a couple minutes and rebooting it does the trick. However, sometimes I've seen this not work, and it had to be done from the Management Station (something you don't have access too... its usually located in the Head End and is remotely accessable from the CSR office - usually) before it dropped it.

The other alternative is to buy extra IP addresses.
So if you are going to hook up more than 1 PC, definately get a router.

3)You shouldn't need an amplifier if your lines are set up right. Which they probably aren't.
How many outlets do you have? How many splitters are there inside the house? What do the fittings look like? What KIND of splitters are you using? What do you mean signal is weak, what do the pictures look like? What channels are effected?
If you can take pics, and make a list of what channels are doing what, that would help me help you.

If you think about your wiring - think of it like water pipe. The cable signal flows like water - the more times you split off that line, the less water pressure you have, the less signal you have.

Each of your splitters has rating on it in dB
Assuming you have 15db(industry standard) coming in from the pole, the two-way outside will take 3.5db off that.
(Scale starts at -30.0db meaning no signal at all, But as a general rule, you want to keep your levels above 0.0db)

3-way splitters have 1)3.5db down port and 2)7.0db down port.
4-way splitters have 4)7.0db down ports.
6 & 8way splitters are 11.0db down on all ports.
VCR's also drop signal anywhere from 4.0 - 10db they all vary but the general rule is if its bad after the VCR, then it wasn't good going in, easy way to check this, is to look at your picture quality on channel any channel between 2 and 6 when running through the vcr (with vcr OFF) as opposed to striaght into the tv - significant difference in picture quality is indicitive of a problem with either the VCR or the jumper between the VCR and the TV - btw, get rid of your push-on jumpers, they're junk if you bought them from a store)

Less db is worse.
so start with 15 and subtract the appropriate amount for each splitter you encounter on the way to the TV.
Big-Screen TV's you generally want to hit with 5.0db or above - everything else should land at 0.0 db or above. Generally, below -10.0db is very bad. In fact, depending on the carrier to noise ratio (CNR) of the cable system, -10.0db, you may not have a picture at all! However, in a system with a good CNR - you may not see grainy pictures until -15.0db!

So there is a little crash course in cable - let me know what you find.

Matrix · Post by **Matrix** » Sun Jan 02, 2005 2:02 am

Capm wrote:Being a Cable Guy (Broadband Technician, actually) I have a few answers for you....

1) Leave the Modem where the tech put it! DO NOT try to use another outlet, it will not work. (Shouldn't.. anyway, if it was done right) In Cable modem installations, the modem outlet is isolated from the TV outlets by a High-Pass Filter. This blocks the return signal on all the outlets but the one the modem is hooked up to in order to prevent TV's from throwing trash back into the cable system and taking all the modems down.
From the Tap (where your drop hooks into the cable system) to your house, there should be a two-way splitter (or a Directional Coupler) with one leg going to the cable modem and the other leg should have the high-pass filter and then goto the rest of your outlets. That single two-way is ALL that should be between your modem and the tap.

I dont have anything like that, nor have I ever seen something like that. I guess it varries per system.

I just have the one line coming into the house and after that it uses all normal spliters.
Can put the modem anywhere, even someone elses house as long as it is in an area where my cable co owns the lines.

DCrazy · Post by **DCrazy** » Sun Jan 02, 2005 9:05 am

Capm wrote:Being a Cable Guy (Broadband Technician, actually) I have a few answers for you....

1) Leave the Modem where the tech put it! DO NOT try to use another outlet, it will not work. (Shouldn't.. anyway, if it was done right) In Cable modem installations, the modem outlet is isolated from the TV outlets by a High-Pass Filter. This blocks the return signal on all the outlets but the one the modem is hooked up to in order to prevent TV's from throwing trash back into the cable system and taking all the modems down.
From the Tap (where your drop hooks into the cable system) to your house, there should be a two-way splitter (or a Directional Coupler) with one leg going to the cable modem and the other leg should have the high-pass filter and then goto the rest of your outlets. That single two-way is ALL that should be between your modem and the tap. There should be NO SPLICES in the OUTLET or the DROP. NO CORROSION of ANY KIND. If your signal is so poor on your cable modem that you need a cable modem amp, then there are problems that the cable company needs to fix. You should not need a cable modem amp for ANY REASON. They do not effect your bandwidth, either, btw so if you thought you could hot-rod your modem, you're wasting money and probably causing a return path problem in the process by blasting the input of the first amplifier in the line.

I ran my cable internet service through two splitters, and had no filters installed anywhere in the house, and still enjoyed crystal-clear cable and 6 Mbit downloads. Now I only have one splitter, but still no filters, and I have flawless digital cable service.

capm wrote:2) Most ISP's now only allow 1 CPE (thats like, your pc, or a router or other devices that take an IP) Which basicly means, you get 1 IP. This is half of the reason when you hooked up the other machine it didn't work. The other half is because that cable modem learns the MAC address of your NIC card, and since it is allowed only 1 CPE, then any others that hook up to it will be denied. SO.. what you need to do, is get the modem to dump that mac address. Usually, unplugging the modem for a couple minutes and rebooting it does the trick. However, sometimes I've seen this not work, and it had to be done from the Management Station (something you don't have access too... its usually located in the Head End and is remotely accessable from the CSR office - usually) before it dropped it.

Yep. My ISP is a nazi about having more than one computer hooked up to a connection... having a router is against the terms of service. Luckily, they really don't enforce their policy (I've even had techs diagnose my connection and read the fact that I've got a Linksys router hooked up).

The other alternative is to buy extra IP addresses.
So if you are going to hook up more than 1 PC, definately get a router.

Capm · Post by **Capm** » Sun Jan 02, 2005 10:09 pm

I dont have anything like that, nor have I ever seen something like that. I guess it varries per system.

I just have the one line coming into the house and after that it uses all normal spliters.
Can put the modem anywhere, even someone elses house as long as it is in an area where my cable co owns the lines

I ran my cable internet service through two splitters, and had no filters installed anywhere in the house, and still enjoyed crystal-clear cable and 6 Mbit downloads. Now I only have one splitter, but still no filters, and I have flawless digital cable service.

Just because it works, doesn't make it right or even desirable.
Modems and Digital devices will work through alot of things that they're not really supposed to. (Also note that digital signals are generally sent out 10db below the analog carrier.) I've seen them work perfectly in very bad situations. But inevitably, it causes problems.

And a cable modem will work on any enabled outlet that is in the service area of its CMTS (Cable Modem Termination System). Physical location means nothing to it.

Jesus Freak · Post by **Jesus Freak** » Thu Jan 06, 2005 3:14 pm

OK I found out from my ISP. They told me all I need to do is release my IP by going into network connections and turning off "Automatically detect LAN Settings" and turning off automatically detecting the DNS. Just so u all know. Thanks for the extra info though. I will use Matrix's command prompt "ipconfig/releast *Con*" and if necessary on my other pc "ipconfig/renew". That is very simple. I will figure out the router business once I get a wireless one.

Jesus Freak · Post by **Jesus Freak** » Sun Jan 09, 2005 11:14 am

ok, doing a bit of experimentation. Looks like it is not enough to just release the IP and renew it. It tells me I have to do something about a DHCP server or whatnot. I'm gonna try exactly what my ISP told me in terms of turning off automatically detecting IP and DNS and see what happens.

Capm · Post by **Capm** » Mon Jan 10, 2005 10:38 pm

Read what I said man -

Its not as simple as releasing the IP on your machine.
You have to get the cable modem to drop your PC's MAC address (the physical address hard-programmed into your network card). Unplug your PC from the modem, and unplug the power from the modem. Give it a minute or two, plug the power back into the modem, and let it come back online, unplug it again(redunant, yes, but just to be sure), hook the router up to the cable modem. Plug the cable modem back in. It should learn the MAC address of the router now. Plug your pc into the router, manually set your ip to 192.168.10.4 or something, (look up the default IP of your router and change the last number) then using your browser, log into the router (usually, its - http://192.168.10.1 look it up in the routers manual ) default user/pass is either blank or admin/admin usually. Go into the status screen and make sure it is pulling an IP. From there you should be able to get your other PC's online. Enable the dhcp server in the router and set your PC to auto-detect, reboot PC.

Matrix · Post by **Matrix** » Tue Jan 11, 2005 11:48 am

He had already tried that capm, we fixed it yesterday tho.

The way he had talked before made it sound to me like he had the modem working on a few different computers, just not the router. Thatâ??s why I didn't think it was the MAC addy, but then he told me he could only get the IP to renew on the 1 comp, so I had him clone his NIC MAC into the router. That fixed it.
Seems like his ISP only allows 1 MAC, because no matter what he did the modem wouldnâ??t release correctly to allow a device with a diff MAC to work. Power cycling and everything did nothing.
With my modem I can just release my IP, plug it into a diff device, renew and it works. I don't even have to unplug it.

Capm · Post by **Capm** » Tue Jan 11, 2005 7:58 pm

Sometimes the modem has to be reset from the CMTS management station for it to drop it. =\

Jesus Freak · Post by **Jesus Freak** » Wed Jan 12, 2005 4:26 pm

Anyhow, I got my router working now on my pcs, so it's all good