Multiple Mac addresses on one connection? Is this possible?

mithrill · 05-12-2005, 09:34

My mother currently gets her broadband via NTL she has the 2MB connection in Surrey (not sure if the location makes a difference with NTL). She has a fairly old terracyon (Model: 210) modem which she got from NTL. Internet works fine when a computer in connected (using the ethernet port) directly to the modem. The issue arrives when trying to set up multiple computers to use the same connection. I have attached a (known to be working) router/switch to the modem and then 3 computers and a PS2 to the router. Each of the computers works on the internet individually, however in order to switch between them the modem needs to be reset. Through much diagnostics and messing i have managed to pin this down to the mac address (i think). Either the ISP stores the mac address somehow or the modem is storing the mac address and limiting connection to this mac address. This puzzles me greatly and goes against most of my knowledge. All can connect to the router (responds to pinging and can access the admin screens), but only one at a time can connect to the internet. Is this a common problem/deliberate NTL restriction? Is there a workaround? Should i just buy a new modem? Should i just change broadband from NTL to another ISP?

hayesey · 05-12-2005, 10:13

My guess is that the "router" you are using is in fact a switch or a hub. You need a router or else only one PC will work at a time. Your modem is only capable of sending network traffic to one address & with a hub or switch it'll only send traffic to the last address it sees. A router is more "intelligent" & can route traffic to a number of IP addresses on a network. What is the make/model of your current device?

If you need a router I can recommend Linksys stuff as it's pretty cheap & good stuff.

Stuart · 05-12-2005, 10:15

to Cableforum.

Are you sure you are connecting a router? TBH, it sounds like you are connecting a switch or hub.

If it is a router, NTL would not have a reliable way of detecting how many devices you have attached. I'll admit, they can get enough info to have an educated guess, but they don't know for sure.

Could you post the make/model number of this "router"?

mithrill · 05-12-2005, 10:29

Yeah i am very sure, it is a U.S.Robotics (8000A) router. I have also tried a netgear wireless "DG834G" router, although i can't get even one computer working with this (even using the wired ports). They both have an uplink port which i plug the modem into and four normal ethernet ports.

Just to clarify some of my diagnootsics...
I had two computers, computer A and computer B both setup to use DHCP.
I plugged one computer (computer A) into my modem, reset the modem and the internet worked on it.
Removed the cable from computer A and put it into computer B. The Internet did not work (there is certainly no DNS resolution, didn't actually try putting in a specific IP address). Then i reset the modem and the internet worked.
Removed the cable from computer B and put it into computer A. The Internet did not work.

Stuart · 05-12-2005, 10:48

Well, according to Netgear, the dg834g is a wireless ADSL router, so that's probably why it's not working. If your mother is in an NTL cabled area, then NTL do not use ADSL to carry broadband. They use the cable.

As for the US Robotics router, well, they do various routers (both ADSL and Cable), so I do need the model number.

mithrill · 05-12-2005, 11:00

Sorry i edited my post rather than putting a new one with the model number in. It is a U.S.Robotics "8000A".

I wasn't aware that the router would "care" about the broadband type. What then is the difference between ADSL and cable for broadband. The netgear router doesn't actually contain the ADSL modem, but uses a bridge style mechanism for communitcating with the modem (which i disabled for use with the terracyon modem), but that's a different and mostly unimportant question.

Stuart · 05-12-2005, 11:27

Quote:

Originally Posted by mithrill

Sorry i edited my post rather than putting a new one with the model number in. It is a U.S.Robotics "8000A".

I wasn't aware that the router would "care" about the broadband type. What then is the difference between ADSL and cable for broadband. The netgear router doesn't actually contain the ADSL modem, but uses a bridge style mechanism for communitcating with the modem (which i disabled for use with the terracyon modem), but that's a different and mostly unimportant question.

The only difference between an ADSL router and a Cable router is that the ADSL one includes the modem. The model number you gave for the Netgear is listed on their site as an ADSL router.

Any router that works on NTL cable just has an Ethernet port, so will actually work with ADSL (as long you have a seperate modem with an Ethernet port).

According to the quick setup guide on their site (http://www.usr.com/support/8000a02/8...global-ig.pdf), then you USR router should work.

I would suggest unplugging both the router and the modem from the mains. Also unplug any PCs from the router. Now plug the router into the modem and plug the modem back into the mains.

Now, plug the router back in. Give it around 30 seconds to complete any diagnostics and plug the PCs in. You might need to reboot the PCs.

If that doesn't work, try unplugging both the Modem and router from the mains. Then plug the modem in.

Now, hold the "RESET" button on the router and plug it in. Keep holding the reset button until the system led flashes. This will return the router to fsctory default settings.