AT&T DSL modem won't link to my Linksys router

Hey all,

First off, thanks for reading and any help you might be able to offer! I probably should have posted in the Network forum, but there's not many people there.

Here's the problem:
I just moved and got AT&T DSL hooked up. They sent me a Siemens Speedstream 4100 modem. I have a Linksys BEFSR41 router (wired only, 4 port ethernet).

Now I can't get the router to recognize the modem. On the front of the router are LEDs for each ethernet port and the WAN port. The LINK LED just won't light up no matter what I try - which signals that the router won't recognize the modem. The modem recognizes that the other end is plugged in (via the Ethernet LED).

The thing is that the 4100 modem has the PPPoE authentication on it, which works fine. I can hook the modem directly to my computer and everything works fine. So it must be the router-modem connection.

I've tried:
Having the router get an IP automatically from the modem.
Changing the router's IP address.
Having the modem pass PPPoE authentication to the router.
Bridging the modem.
Power cycling the guts out of everything.
No matter what I do, it never lights up the LINK LED. Its driving me nuts! I'm hoping someone's experienced a similar issue and can help me out?

Thanks, I did try that, but to no avail.
I don't think its dead, it just may be that the router is too old for the PPPoE on the modem configuration. :-(

That's the only thing I can figure that went wrong. Course, it could be dead, but i'm too lazy to find out. I ended up just getting another wireless router since i'll need it for my wii anyways.

Thanks for the help!

yeah I tried setting up the router to accept an automatic IP address from the modem (which should happen w/ PPPoE on the modem), but it still didn't work. Maybe evongugg is right w/ the dead port/router idea. :? Its all good now since I got a new router.

I have the same issue with my WRT54GS. Recently I got DSL and I'm trying to hook up my Siemens 4100B modem to my Linksys WRT54GS, but so far I'm having zero luck. Running directly off the modem works fine, but the minute I bring the router into the equation everything goes south. I have configured the mode/router as follow:

1. configured the modem to bridged.
2. plug in model to WAN port on router.
3. configured router to run in PPOE mode.

No luck, I know the router is port is good because It works with Cable modem.

Have you tried a crossover cable? If you're not getting a link light, messing with the IP settings will get you nowhere.

EDIT: Replying to the OP. Goofy "Post Reply" button is randomly replying my posts to various folks.

I did try the crossover at the begining. Thanks.

Also, the version of the firmware I'm using is 4.71. Is anyone using this version with the PPOE configuration?

Oh yeah sorry about that, but my suggestion still stands. I think it could be related to the subnet mask on the modem as well.

I highly doubt that the modem is configured to allow only 1 MAC address. That would be a nightmare for consumers and ATT.

Also, remember when you do a IP change, do a ipconfig /release and a ipconfig /renew to get your new IP address from the router.

How my netgear is set up is I have PPPoE on the modem and the modem is set to always provide the connection to the router with a specific address (192.168.64.1? - from my months old memory).
The netgear is 10.0.0.1 and to automatically get the IP address from the router (akin to how a cable router is set up). Then DHCP is handled by the router to my computers.

Another note, you can try to disable as much as security as you can on the router until you get it to work. After I make it work and I've got the correct settings up and going, then I reenable my security.

Just out of curiosity since you moved, and now have I assume a different modem, did you reset the router to its default settings, using the reset switch?

Oh yeah. Multiple times. And then another one for the heck of it.

Flasher, you have revived my technical curiosity in it. I had solved the issue by just getting a new router because I realized I would need wireless anyways. But I will contemplate some extra investigation this weekend and see what happens.

I know the modem works fine because the modem's ethernet LED would light up is if I bypassed the old router and went straight to my computer. I'm relatively sure that the router is ok - it was when I decommissioned it. I know the switch part works, it was just the WAN LINK port that would not recognize the modem.
The router does have auto-detect crossover or straight (at least according to the data sheet). That was one of the first things I thought of and double checked. I've tried different cables. Did not think about trying a port on the switch though - i'll have to give that a shot to see if the physical layers will recognize each other.

Router to computer is fine. I have an IP from the router's DHCP and can ping, etc. Its seriuosly just the path between the router and modem. And since I've verified the modem works, its down to the router.

So pretty much I figured the WAN port was either fried or dead and just got a new router since I had to to go wireless anywho.

Oh another thing I just remembered - the modem's Ethernet LED would light up when I plugged it into the router, but the router's would NOT. That was what confused me - it seemed like the modem knew the router was physically there, but the router was refusing the acknowledgment or something. That's why I pursued the upper layer protocol methods.

I like the goblin theory... Thanks for the ideas, I'll post back next week. If you have more ideas, love to hear them.

Hey Flasher, I would have posted back last night but the forumz were down for this overhaul. Kinda hate how the quotes are working right now, but that's a different issue.
Yep, it is indeed a wacky problem. One that drove me bonkers and caused about a week of troubleshooting. I tried plugging the WAN port of the problem-router to my good router's LAN port. As before, good signal on the good router showing a connect, but the WAN LED's on the problem-router were blank. I reconfirmed by going LAN to LAN and both routers were happy there. I will try the problem-router to my computer sometime. It is Auto-crossover, so unless that broke, I think I'm safe to put that theory down.

Currently my line of thought is that the WAN port on the problem-router has been fried/heat damaged, but still allows the physical layer to connect on the other side. Or that there is some obscure Linksys compatibility issue at hand. I have seen some similar reports online to the same effect. I'm not sure in what cases the Link LED will light up on the problem-router (some Linksys specification of some sort that only allows it to light up when its being an actual router??). As you can tell, I'm just pulling theories out of no where to explain it.

does you dsl link light go off or flash when you hook this to the router?

ATT likes to set their modems up to use the 192.168.1.x subnet, which is also what the Linksys (and many others) router uses by default. Hook everything up as normal and leave the router set for DHCP from the modem. Now change the IP of router to 192.168.2.1. The router will reboot, you'll also need to renew the IP on your computer (make sure it gets a 192.168.2.x address) and now you should be good to go.


aa

I'm trying to migrate from Comcast cable to AT&T DSL. I've run into all the stated issues. Except one. I noticed in Network Connection Details (in Windows Vista Home Premium) this setting:

Connection-specific DNS Suffix: hsd1.ca.comcast.net

I can't figure out how to undo it. I even reset my Linksys WRT54GS router to factory defaults. If this suffix is being added, though I'm not very technical, could it cause cause connectivity to fail between the router and DSL modem?

Thanks! it worked for me after following mtasker's suggestions.
Before that I was strggling with both zyXel and Linksys routers with Motorola modem. by default all of these three use 192.168.1.* IP range.
After changing IP address range of Linksys router from 192.168.1.* to 192.168.2.* it started working.

Let me provide a little insight, from the perspective of a phone company technician who fixes phone lines and DSL service (including on-premise issues). I'll start by saying that we are not allowed to touch customer networking equipment that is not provided by AT&T. Computer networking is a much more complex set of issues than merely getting the DSL to work. That said, I have a network at home, and I have built networks using both MS Server software and Novell. My home network is Linux (OpenSuSE). So, I'll occasionally assist a customer in getting their DSL working through a 3rd party router, but only if they have some idea what they're doing. If a child set up the network and the parent is the only one home and has no clue, I'll generally prove the DSL working to my laptop and let the customer's child re-setup the network.

Here are the troubleshooting steps which we perform in order to get the DSL working.

• First & foremost is to get a signal to the DSL modem (it can be any of the modems we've provided in the past, the 2-Wire home portals, or the Cayman/Netopia routers - we don't provide the Cayman/Netopia routers as a self-install option, only as a full-tech-install option).
• [*]Troubleshooting the DSL signal to the modem means confirming that there's dialtone to the modem (or continuity, on a dry loop [DSL w/o phone service]).
• [*]Then we check to make sure everything is properly filtered. Note that any device (other than the DSL modem) that is connected to the phone number MUST be filtered. This list of devices includes anything connected ANYWHERE that the phone number exists, and such devices as telephones, answering machines, caller-id boxes, fax machines, sattelite dish boxes, and, yes, especially burglar alarms (burglar alarms won't necessarily kill the DSL signal, but 99% of them eventually do - they may not "malfunction" immediately, but it can [& will] happen within 2 seconds, 2 minutes, 2 hours, 2 days, 2 weeks, 2 months, 2 years, etc., from the time of initial installation - so we suggest that we either do a full-tech installation or that the customer have their alarm company come install a filter on the alarm).
• [*][*]Assuming that there is a signal to the house (as measured at the phone company box, usually outside the house and located somewhere near the electric meter), then there should be a good signal to the end of the phone cord that will plug in to the modem. If there's not a signal there, but is outside, then there's something wrong with the house wiring ("IW" - Inside Wiring), which must be fixed before the signal will reach it's destination. We'll presume that the signal is now at the modem and is evidenced by a green DSL led on the modem. We use a test device to confirm the signal is present, and if it is present on our test device but not on the modem, then we simply replace the modem. From this point forward, we'll assume that the modem has a green DSL LED. There is one 2-Wire Home Portal that has a 3 state LED: Red for no signal, Orange for a signal but customer isn't registered, and Green for signal AND registered. For this device, an Orange broadband LED is ok.
• Next, we'll connect the computer DIRECTLY to the modem, via ethernet cable. We'll use the customer's computer, assuming it is operating correctly, or we'll use our own technician's laptop. Either one is fine, but our laptop is almost always functioning properly. It is now time to get the customer registered and enter the registered username and password into the PPPoE client that exists on the modem. There are a few modems out there that do not have PPPoE built in, and those require either a router with PPPoE or a "broadband" connection on the computer. We no longer support those modems as they are out of date. However, if a customer has one & it will work, I will usually attempt to get them going with it.
• [*]To confirm that the (customer's) computer is working properly, we'll surf into the IP of the modem/home-portal/router (I say "router" here, but am specifically referring to the AT&T provided Cayman/Netopia series routers, not 3rd party routers such as D-Link, LinkSys, E-Home, Belkin, - & the list is as long as everything I'll type into this post). If we can surf INTO the device using the IP address, then it would appear that everything is ok (with the possible exception of DNS settings, but that's a different issue than this one here).
• [*]If we do get the device setup screen, then we confirm that the PPPoE shows the "default" username and password. I can't tell you what these are, because it's supposed to be proprietary and not public knowledge, tho we do show it to our customers if they're watching us.
• [*]Then, we go to the registration website and get the customer registered. If everything works correctly, the customer pick out an email address (that can never be changed after it's registered to that phone/account #), and a password. The registration process goes a little further and then it SHOULD automatically reprogram the username and password into the device. But, to make sure, I always go back to the IP of the device and confirm it's there, or put it in manually. I usually put it in manually because I do not fully complete the entire process - because some of it is downloading software and I don't want/need the software on my company provided laptop (especially after the 100th time I've done this) - it takes too long and we don't use it, so I bypass that.
• Once the username (email address) & password are programmed into the device, we surf. We usually go somewhere like cnn.com or weather.com - because they are always changing and we can tell that we're live & online. If it's a 2-Wire, and the customer has 1 computer to be connected wirelessly, I'll usually assist in that, or do it for them. I may not do 2 or more, but might, depending on my workload and where I are in the day & how long it's taken us to get that far, and if the customer has been respectful or abusive. If it's a router (AT&T provided Caymen/Netopia) and the ticket has the code to install jacks & cables & computers, I'll do whatever the ticket requires - up to connecting and surfing on 4 computers - We WILL NOT EVER configure printers for sharing and especially not configures file sharing -> That is up to the customer's "certified networking professional" because we will not be liable for potential security breaches among computer users.

Providing that we've been successful to that point, we attempt to get the customer's computer connected & have him/her surfing to prove that it's working. If we can do this, then our responsibilities have been fulfilled - we've proven that our circuit and our AT&T provided equipment is working properly - even if we can't surf from the customer's computer, we'll prove it from our own. If we can't surf from the customer's computer, but can from our own, we'll do some cursory troubleshooting on the customer's computer. We'll make sure the network card is properly configured and that the IP & DNS settings are properly configured. This is all dependent upon it being a computer running either Windows XP or Vista. If it's a Mac computer, I am probably less knowledgeable than the customer and will explain the concepts and watch as the customer does the configuration themselves.

Now, if the customer also has a 3rd party router to be inserted between the modem & his/her computer, we are not allowed to touch that. However, because of my networking background, I MIGHT (see conditions above) attempt to get it working - if it can be done quickly.

• There are two ways, generally, to configure the two devices so that the customer can surf from 1+ computers.
• [*]Leave the modem configured with the PPPoE in it, and set the router to grab an IP address from the modem. Replacing the modem in this condition requires that we have the customer's username (available on the phone bill) ans password (not available anywhere and must be reset online if the customer has forgotten/lost it). This is the default, but it can be a pain to replace the modem like this. Or, one can ...
• [*]Set the modem to "bridged" mode, where it is nothing but a dumb modem with no IP configuration or anything, and configure the router to handle the PPPoE. Remember, this is done AFTER all the above configuration has been done & proven it works. Once the modem is configured to bridged mode ("bridging the modem" ), it becomes 100% transparent to the entire process from either end with the exception that it changes the DSL signal riding on dialtone to an ethernet signal transported on 10T/100T to your router. To do any further configuration of the modem, after it's set in bridged mode, the modem must be reset to factory specs using the itty-bitty-tiny-whiney little button that performs this function - you can't even get into the modem from the computer, even directly connected, without doing a full reset. When it's done this way, it's easiest for us to replace the modem because we don't even need to know the customer's username or password.
• [*][*]In either event, generally, the default settings will work correctly so that the customer can surf from multiple connected computers. Specific applications, such as remote monitoring of a security system with cameras, gaming, etc., are all up to the customer to configure the router for such specific tweaks.

Finally, a quick recap.

• If the DSL LED on the modem is not green (with the aforementioned exception), stop there & make sure everything is properly filtered or that you connect the modem outside at the phone company box with the jack inside. Do not pass go, and definitely do not collect $200. If the DSL light is red, you're dead.
• Connect the computer directly to the modem and get registered and surfing before connecting anything else. If you can't surf with just the modem between the computer & the phone line, you definitely won't be able to do it with a router also inserted.
• Any other networking devices connected other than AT&T provided equipment are the sole responsibility of the customer - I (or your friendly technican, if capable) MAY do it when we're out there on a service ticket, there may or may not be a charge for it, but we are not certified networking professionals and you definitely don't want us (not even me) connecting and configuring anything more complex than the most simple configuration on the router.

Hope this helps!

The modem doesn't have any info regarding phone number in it. It only has username & password for the AT&T DSL account. I've setup hundreds of these. If the modem isn't bridged, then it's actively using it's PPPoE client to login to the Internet. It will work any place there is a DSL signal on the phone line, and it's completely independent of the phone number. Now, you HAVE to register your username and password with the phone#, or else you'll just be using someone else's, and they can lock you out with a password change. But, there is no memory for the phone # in the modem. The modem doesn't care what the phone# is, as long as there's a DSL carrier signal on the copper.

Yes, the IP address change fixed my problem as well. Even though ATT's instructions said to bridge the modem, I knew that wasn't necessary because it was working fine before (set up by somebody else) without being bridged. I needed to reset my router to reset the passwords. Nothing was working after that until I saw cecil14's comment about how ATT's modems use the same subnet as the default for Linksys. As soon as I changed the router IP address and repowered everything (power up the modem first, then the router), I had Internet on the LAN using automatic configuration (the cable modem option). I did clone the MAC address from the PC which was previously hooked up directly to the modem and had working Internet, but I'm not sure if that was necessary. Thanks for the tip!

Hi Cecil14
This worked for me.....
Saved me $99 from AT&T plus .....

Regards,
Lebon

Nice to see it wasn't only me having problems with ATT DSL. Have a linksys providing a Wireless N network and ATT came with a 2wire dsl modem/router combo.

In the end changing the IP address scope of the 2wire to the 10.0.0.1 range and enabling DHCP to assign the 192.168 range on the linksys did the trick.

I'm now trying to help my fiancee set up a belkin wireless G with a legacy SBC yahoo modem. Unfortunately I can't see the Belkin interface in front of me so it's an arduous process. Will check back with the proper solution for an old school sbc yahoo dsl modem and Belkin wireless router.

Yes!! I practically have the same problem. Speedstream 4100 B and a Linksys BEFSR41 v.3. Now, ATT claims to only support the Speedstream . Linksys tried but after a while it was back to sq1........

Thanks for the offer and the info in advance........!

Also, with my static IP's, should I reconfigure them to be 2.xxx instead of the 1.xxx I'm currently using?

-Paul

Thanks so much mtasker, so simple, just changed router to 192.168.2.1, restarted everything, and it worked fine.

ATT customer service is HORRIBLE.
Graham

I have a Linksys WRT54G wireless router which is notorious for losing the signal from the modem on a fairly regular (3-5 time weekly) basis. The only solution is to unplug the router, wait aboyt 15 seconds, plug it back in, and it will work MOST of the time until next time. I went online and read 12 costomer reviews of this router, of which TEN were between bad and horrible. I wouldn't hit a pig in the behind with a Linksys router. By the way, I DO NOT have ATT internet.

I found this forum before I signed up for AT&T DSL, did not want to use thier gateway, since I already had Draft N. Set my Airlink router to 198.168.2.1, instant connect. This forum saved me alot of grief. Thanks a million.