The joys of setting up a router... (semi long?)

[Gonk]

So lets get down to business. I recently moved (very very long story), and have recieved a nice shiny new cable modem (Terayon TJ715) from my cable company (Adelphia). I also have a Linksys WAP/Router w/ 4-port switch (BEFW11S4 version 2, 802.11b compliant, blah blah). Now with my last cable modem (some RCA thing, which is now long gone), the router worked perfectly fine. I had my connection shared with this computer, my other PC, as well as wirelessly with my laptop. The problem is, when I moved, and got this new cable modem, that stopped. I can LAN perfectly fine across the 3 computers, but none of them can access the internet when the cable modem is connected to the router. If I connect the modem directly to the NICs on any of the computers (i.e., only one at a time), they all work perfectly and can access the internet without a hitch. The problem seems to be getting the cable to recognize the router, and vice versa.

Just to clarify a bit. I currently have the cable modem connected to this computer's NIC with a straight (patch) cable, but the odd thing is it's a T568A - T568A cable (this is the cable that came with the modem, btw). I can use a T568B - T568B straight, and that works perfectly fine as well, when connected directly to a NIC. Now the problem arises when I connect the cable, via a straight cable (either the A - A or the B - B straight cable) to the router's WAN port. When that happens, the diagnostic LEDs on the cable modem itself don't all light as they should. The Power and Cable lights light as normal, but the PC and Data lights do not come on at all, suggesting that the modem is not "seeing" the router or the computers beyond it.

The router is set to act as a DHCP server for my LAN. Thus is should be getting an IP for itself from Adelphia's DHCP servers, and yet it doesn't seem to do so. It's LAN IP is 192.168.1.1, and it correctly configures the clients to use that as their gateway, but for some reason, again probably a communications problem between the router and modem, it will not get an IP from Adelphia's DHCP, and thus I cannot access the internet from behind the router, regardless of which computer I use.

The three computers are as follows: PCs (both of them) are WinXP home, Laptop is (agh!) WinME (I don't currently have the cash to upgrade it to XP at the least so I'm stuck with this horrible demon of an OS..). They all have TCP/IP installed, and all are set to obtain DNS servers and IP Addresses automatically (thus setting them up for the DHCP server that is the router). They all recieve IPs accordingly from the router. So it's nothing from the LAN side of things. The WAN side of things is the snafu, if I'm guessing correctly.

I've had suggestions to fix this as per the following: Get a crossover cable, and attach it from the modem to the router's WAN port and see if that works (which seems odd to me since that's not what crossovers are used for), try cloning the MAC address of the NIC card on one of the computers so that the router appears to be the NIC card, try different straight cables between the router and the modem (which I have, 5 different ones, in fact, and none have worked), and just shoot the damn things and be done with it.

The last one is very tempting.

I have yet to try the MAC address clone, as that seems a bit drastic to me, and it wasn't required by the last modem to work correctly. (BTW, again this is a long story, but I now using a different account with the same ISP. The first was my father's account, this new one is my own.) I am unsure if Adelphia requires registering of a NIC's MAC address or not, but it doesn't seem likely as with the last cable modem all I did was connect everything properly (and with all straight cables), and it worked flawlessly. I don't currently have a crossover cable to toy with, though I can easily get one or simply terminate one myself. The crossover cable again seems like an odd way to correct the problem, as crossover cables aren't typically used to connect cable modems to router WAN ports... I'm really stuck as to what to do, as I'm fairly sure the problem resides between the router and the cable modem. The LAN works just fine, it's accessing the internet that's the problem.

Any suggestions?

 

[Transition]

Well, you might want to just save yourself some troubles and see if the company has anything in their TOS against multiple computers using the service. Tell them you have a wireless AP hooked up to the modem, and it doesn't work (you could even just tell them you have one computer accessing through the WAP to be safe). They might know something you don't..

I had a similar problem lately with a router behind a cable modem not working. I ended up just pulling both the plugs on the modem and router for about 2 minutes. Plug the modem in first, ensure a connection is established, then put the power back on to your WAP. Sounds dumb - but worth a shot if you haven't already tried. Crossover cable is worth a shot, although highly unlikely to fix the problem.

Also, you might want to try cloning your MAC to your cable modems MAC - see what happens. But i'd definitely just start by calling the company and asking.

 

[Gonk]

Well, I checked out the TOS soon after posting this, and while home networking isn't strictly forbidden (and, honestly, they can't stop you from doing it), it's also unsupported. So I doubt calling them would do any good.

That said, how do I go about finding the MAC of the modem? I'm fairly certain the one being shown when using ipconfig /all is the NIC on the computer, not the modem.

 

[MichaelD]

The MAC addy of a modem is usually on a sticker on the modem itself. If it doesn't say "MAC address" it may say "modem address" or "modem code."

It's hexadecimal and looks liek this: 3E 9A 1C 3C R7

However, your problem is what you've ID'd already; the MAC cloning prob (my ISP does the same thing)


Whatever the MAC addy of the NIC you were using the VERY FIRST time you accessed your ISPs network, that's what their DHCP/DNS servers are looking for. You need to:

Put that NIC in a box on your network
Find out that box's IP addy (probably 192.168.0.x)
In your routers' WAN access setup, select "clone MAC addy of a box on the network" then put in that IP from the step above.

I've been doing this with my ISP for two years now. No probs at all. In fact, that NIC is long gone...I just don't flash my router's firmware anymore.

ps
You could also call your ISPs customer service and play really stupid. Just tell them the old computer died so you sold it, you have a new one and now you can't access the internet. Be sure that you have that computer connnected directly to the modem. They'll do a feel for it, detect it, enter that NICs MAC and you'll be all set.

Good luck.

 

[Gonk]

well, just tried the MAC clone. Tried it for the NIC on this computer, and the cable modem, no luck on either. For some reason the modem will not recognize the router no matter what I do. Very odd. I'll grab a crossover cable and see how that does tomorrow.

 

[Gonk]

I popped in a crossover cable, and still nothing. The router and modem absolutely REFUSE to work together, no matter what I do, and I just cannot figure out WHY. This is extremely annoying, and the only problem that I can see is the modem itself.. either that or I'm screwing up something relatively simple...

 

[MichaelD]

Originally posted by: Gonk
I popped in a crossover cable, and still nothing. The router and modem absolutely REFUSE to work together, no matter what I do, and I just cannot figure out WHY. This is extremely annoying, and the only problem that I can see is the modem itself.. either that or I'm screwing up something relatively simple...

Are you sure that your modem is still functioning properly? I have had two cable modems die on me in as many years.

 

[Gonk]

Yeah I'm actually using it currently to post this stuff. It works fine when connected to the NIC proper, but not the router. Very strange.

 

[spidey07]

i'm still thinking it is the mac address.

When you plug the router in do you get a link light on the router and modem? How about the PC when you attach it to the router?

Check the syntax of the mac address, it is a 12 digit hex number. you can find it from your PC by typing "ipconfig /all" in a command window.

 

[Gonk]

When everything is connected through the router, the router's WAN Link LED lights up, the Act (Activity) LED does not. As for the cable modem, when it is connected to the router, only the Power and Cable LEDs light. The PC and Data LEDs do not.

Edit: Just tried the MACs of the Laptop's NICs (it has a Linksys 802.11b wireless PCMCIA card and a built in wired Ethernet port), neither of which worked when cloned to the router. I don't have a firewall running on this computer, nor do I have one setup with the router, as far as I know.. that's the last thing I can think of that could be causing this.

 

[Gonk]

Bump! Still need help with this! Anyone?

 

[MichaelD]

Reset your router to the factory configuration...there's either a tiny little button you have to press thru a hole with an unbent paperclip on the bottom, or theres' an actual selection in the menu. It's the router, obviously.

ps
Have you tried other cables? Possibly a bad cable?

 

[Gonk]

Looks like it's definitely the router, and something beyond my control. It looks to me like the WAN port on the router itself is DEAD. I'm looking at the LEDs on the front, and with SOLELY the power cable plugged into it, no ethernet, no wireless connections, the WAN link LED is on. It probably shouldn't be on. Thus I'm thinking, yay, bad router, and yay I can't RMA it (warranty was up in like, january) and thus, yay, I have to go buy a new one, which I don't have the money for. It pisses me off a great deal that I didn't even get SIX MONTHS out of something that cost me $120...