ATT DSL Modem and own router

[Brainonska511]

I ordered ATT DSL for my new apartment today and the lady on the phone was making some BS claim that I wouldn't be able to use my own router with the ATT modem and if I wanted wireless, I'd have to get the more expensive Wireless Router/Modem combo thing-a-ma-jig. It should be fairly straight forward to add in my router, right? Will it be as simple as leaving set to DHCP and cloning the MAC address of the computer I set up the modem/service with, or will it be more?

Update:
It's a Westell 6100 modem/router. After running the setup internet pages that ATT had in store for me (with some associated software), it was all running fine over the hardline. I just set up my router (Asus WL-520GU with Tomato 1.25) tonight. PPPoE on the router works fine and the modem was set to bridge using the advanced configurations page and can thus use my connection over wireless .

It's kind of slow at 768/384, but it's dirt cheap at $20/month. Fast enough for Youtube, and HQ video (sometimes, I have to let it load a bit before playing); Hulu too if I let it buffer for a minute or two.

Thanks for all the help. Much easier than I thought it would be.

 

[Athena]

You don't have to do any cloning -- it's a PPOE connection. Set it up with a direct connection to get the modem provisioned then insert the router between the two and configure it with your password and ID.

Athena

 

[Brainonska511]

Okay. So it's basically set up the connection, take down my connection information (ID + pw), put router in between, change router from DHCP to PPoE and insert appropriate information? Sounds simple enough.

Should I also switch the MTU on the router to 1492 or just leave it at the default (I think it was at 1500 when I was using my cable connection).

 

[drebo]

You'll need to change the modem into a bridge. Sometimes this is referred to as "PPPoE on the Computer".

Alternatively, you can continue to have the modem do PPPoE and provide a public IP via DHCP to an inside device. This might be the simplest way for you to set it up. There is no real performance difference between the two.

 

[Brainonska511]

Originally posted by: drebo
You'll need to change the modem into a bridge. Sometimes this is referred to as "PPPoE on the Computer".

Alternatively, you can continue to have the modem do PPPoE and provide a public IP via DHCP to an inside device. This might be the simplest way for you to set it up. There is no real performance difference between the two.

I think I know how to set up the former one; how would the latter be done?

Is there a special IP address to access the modem, or is it just 192.168.1.1 from when my computer is directly connected?

 

[drebo]

There should be a sticker that has all that information on the bottom of the modem. At the very least, it will have an "access code" which you will need in order to modify any of those settings. The modem's IP address can be found by attaching your computer directly to it, waiting for DHCP to negotiate, and then typing "ipconfig" in a command prompt (start->run->"cmd"). The "Default Gateway" would be the IP address of your modem. What it is depends on what kind of modem you have.

As far as configuring the modem to hand a public IP off to the device behind it, it's a setting within the modem. Exactly where it is depends on the type of modem you have.

 

[Brainonska511]

Originally posted by: drebo
There should be a sticker that has all that information on the bottom of the modem. At the very least, it will have an "access code" which you will need in order to modify any of those settings. The modem's IP address can be found by attaching your computer directly to it, waiting for DHCP to negotiate, and then typing "ipconfig" in a command prompt (start->run->"cmd"). The "Default Gateway" would be the IP address of your modem. What it is depends on what kind of modem you have.

As far as configuring the modem to hand a public IP off to the device behind it, it's a setting within the modem. Exactly where it is depends on the type of modem you have.

Okay, thanks. I guess I'll ask more questions if they come up when I'm setting up my service.

 

[JackMDS]

What they call Modem is probably a Modem/Router.

One solution is to leave it as is and use your Wireless Router as a switch with an Access Point.

Here how, http://www.ezlan.net/router_AP.html

At least start this way until you know that every thing works OK. Otherwise your fiddling with their Modem/Router can end with No service and long time pusing numbers on the phone to get help from India.

 

[Brainonska511]

Originally posted by: JackMDS
What they call Modem is probably a Modem/Router.

One solution is to leave it as is and use your Wireless Router as a switch with an Access Point.

Here how, http://www.ezlan.net/router_AP.html

At least start this way until you know that every thing works OK. Otherwise your fiddling with their Modem/Router can end with No service and long time pusing numbers on the phone to get help from India.

Well, they told me that the "modem" is for just one computer and that is $50 while the "modem/router" is for wireless and multiple hard lines and was $80. I chose to get the $50 one which probably only has one connection on it. I guess if the modem is capable of handing out multiple IP addresses, then I could just do the router --> WAP.

 

[JackMDS]

May be you can find out the Model number and search.

AFAIK the so call modem for one computer is a Modem/Router that has only one RJ-45 port but it can be connected to a switch and work with many computers.

Most people do not know any thing about Networking and the ISPs do not want to spend too much time over the support phone to start teaching people Networking.

Check before you get it YMMV.

 

[drebo]

Originally posted by: Brainonska511
Well, they told me that the "modem" is for just one computer and that is $50 while the "modem/router" is for wireless and multiple hard lines and was $80. I chose to get the $50 one which probably only has one connection on it. I guess if the modem is capable of handing out multiple IP addresses, then I could just do the router --> WAP.

They will claim that it is only for one computer as the router portion of the modem they gave you is only equipped to give out a single IP address via DHCP.

I gave you two potential ways of using your own router (turning the modem into a bridge and having the modem pass a public IP on to your router) which will not put you through a double NAT. Using the router as an access point and allowing the modem to do your NAT might work, except that they're pretty low end. Additionally, you'll have to employ a static IP address scheme, as you cannot disable the DHCP server on the modem.

Both models that AT&T typically uses (a Westell and a Motorola) will work in either configuration.

 

[Athena]

Originally posted by: Brainonska511
Well, they told me that the "modem" is for just one computer and that is $50 while the "modem/router" is for wireless and multiple hard lines and was $80. I chose to get the $50 one which probably only has one connection on it. I guess if the modem is capable of handing out multiple IP addresses, then I could just do the router --> WAP.

Generally, when they say you will only get a modem, that's what you get -- a modem with one jack for the DSL line and one Ethernet Jack. If you get something else, post the make and model here.

 

[Brainonska511]

Originally posted by: Athena

Originally posted by: Brainonska511
Well, they told me that the "modem" is for just one computer and that is $50 while the "modem/router" is for wireless and multiple hard lines and was $80. I chose to get the $50 one which probably only has one connection on it. I guess if the modem is capable of handing out multiple IP addresses, then I could just do the router --> WAP.

Generally, when they say you will only get a modem, that's what you get -- a modem with one jack for the DSL line and one Ethernet Jack. If you get something else, post the make and model here.

Sure thing. I'll post an update when I get the equipment and/or start to set up stuff the way I want.

 

[Brainonska511]

Update: I got the modem (but the model escapes me at the moment). It is a single-10/100 port modem/router (says modem router on the bottom) and gives instructions for how to get to advanced settings. After I set up my connection tomorrow, I'll go about putting the router/modem in bridge mode so I can use my own router for wireless and handling QoS, etc... or at least set up my router as a dumb AP for the time being. Thanks for all the help.

 

[vailr]

If you wanted a backup modem, should be possible to find a cheap (<$20) Siemens Model 4100 DSL modem on eBay.
That's what ATT used to distribute for their DSL service, and what I'm still using.

 

[dman]

Originally posted by: Brainonska511
Update: I got the modem (but the model escapes me at the moment). It is a single-10/100 port modem/router (says modem router on the bottom) and gives instructions for how to get to advanced settings. After I set up my connection tomorrow, I'll go about putting the router/modem in bridge mode so I can use my own router for wireless and handling QoS, etc... or at least set up my router as a dumb AP for the time being. Thanks for all the help.

I think the gotcha is that if you call in for support if/when the internet is unavailable they won't be able to assist troubleshooting with your own router in the mix. So, you have to lie or go through the extra steps of taking it out of the mix.

On the plus side, with DD-WRT I have configured my router (following online instructions) so I can access the modems web page from inside my network. This way I can see/change the DSL modem's config without changing any wires. It required some custom admin strings, so I don't think you can do that with other non-custom firmware routers.

1) During the initial setup (PC connected directly to the modem): Set modem to use IP 10.0.0.1 as it's home page (instead of the default 192.168.1.254) [You'll need to use Static IP's in the same range as the modem, so, sort of a minor pain to set that part up]

PC connected to dd-wrt router:
2) In the startup script section of dd-wrt, add:
ifconfig vlan1:1 10.0.0.2 netmask 255.255.255.0 broadcast 10.0.0.255
and
3) In the firewall section add:
/usr/sbin/iptables -I POSTROUTING -t nat -o vlan1 -d 10.0.0.0/24 -j MASQUERADE

Then I can get to my DSL modem from 192.168.x.x to it's config page at 10.0.0.1 now.

 

[tk149]

I actually just replaced my ATT DSL modem yesterday. Both the old one (broken) and the new one are definitely just modems, not routers - only one output RJ-45 jack.

I also had to set my LinkSys router to a different IP address, otherwise there was some kind of conflict.

 

[Brainonska511]

Originally posted by: tk149
I actually just replaced my ATT DSL modem yesterday. Both the old one (broken) and the new one are definitely just modems, not routers - only one output RJ-45 jack.

I also had to set my LinkSys router to a different IP address, otherwise there was some kind of conflict.

Mine is a router/modem with one RJ45 jack and it has an IP address at the end of the IP range. Of course, ATT didn't activate my service yesterday :| and their customer service doesn't know why.

 

[drebo]

Originally posted by: tk149
I actually just replaced my ATT DSL modem yesterday. Both the old one (broken) and the new one are definitely just modems, not routers - only one output RJ-45 jack.

That doesn't mean anything.

Originally posted by: tk149
I also had to set my LinkSys router to a different IP address, otherwise there was some kind of conflict.

That means that your modem is also performing NAT, which means that it does have a router component.

 

[Brainonska511]

Ugh, turns out it won't be activated now until 6/9. The tech needs access to the building to get at the telephone lines. Of course, the sales person failed to inform me of such a requirement :roll:

 

[Brainonska511]

Update in OP.

Thanks guys for the help.