• Welcome to Hurricane Electric's IPv6 Tunnel Broker Forums.

Are you using a DSL Connection??

Started by UltraZero, February 04, 2011, 08:22:08 AM

Previous topic - Next topic


When I had DSL I had my modem in bridge mode because I had statics and that's the way they did it.  It was preferred that way anyway so I could use my iptables firewall instead of the speedtouch.


I have it running, Speedstream 4300 bridge mode => Netgear WNR3500L running DD-WRT.
The Netgear has the tunnel and provides full dual stack to my home network.

I have had it running with the 4200 and 4300 modems unbridged but always in the DMZ.


I'm just trying to figure out why the need to put the modem in bridge mode.  I've tried it, but, with no success.  My problem is configuring the connection.  I'll keep trying .  I know I am either mixing something up or missing something.  Between PPPoe, Dialer, user IDs, DHCP, access lists, I've got my hands full.

Anyway, the non ppp connection has always seemed to work.  I am trying to figure out why i can't connect to  HE via a tunnel. I wish there was someone who could tell me why bridge mode would work vs standard mode.

I just like to know why (if this is the problem) protocol 41 seems to be blocked, but, in bridge mode it might not be.



When you put your modem in bridge mode, it will pass all traffic through untouched, instead of acting as a router and possibly filtering something.

Though, there might be some miscommunication in terms here. If your modem is not acting as a router (ie, handing out DHCP addresses to your internal network and performing NAT), then it is very unlikely to be the culprit. If AT&T has stated that they are blocking protocol41 traffic, then you need to yell at them to stop filtering your internet traffic. It is impossible to set up a 6in4 tunnel with protocol41 being blocked (as protocol41 is the ipv6-in-ipv4 protocol number).


Thanks for the repsonse.

My modem is currently setup to negotiate PPPoe and to obtain an IP address address.  I setup my router to perform the NAT process.  I guess I am kinda stumped (Rip Van Winkle again, sleep for 10 years and modems change) I thought a modem modulates/demodulates and that's all.  The unit I have I as far as I know does pppoe or not.  Semens 5100 modified by ATT.  What I don't understand is some people are running fine with DSL.  Given I am not in the Bay Area, I would think ATT would have the same policies for running their network regarding protocol 41 everywhere.   

((I am thinking)) it is either my modem or ATT.  I have tried this with Windows 7 direct connect to the modem and the same thing happens.  Pinging IPv4 is o.k. but not IPv6.


the best thing is for you is create pppoe dialer on cisco 3640 and turn your modem in bridge mode. you do not need to forward any thing. enable nat on your cisco router and done.

i also have the same problem but i have not any cisco router at home. i am using gogo6.net tunnel i am able to get connected with it. and you dont need to update your ip address again and again.


I don't understand why this thread is so long.

You said in your original post that ATT won't pass you protocol 41...no protocol 41 means no 6in4.


Well, the reason is because I spoke to someone at HE who has ATT DSL and it works for him.  Also, someone else online has DSL.  Soooo.

Something is rotten in Denmark.  Get my drift???    ::) ::)

If people have DSL and so do I and they are working, I want to know how and why.

I think a good technician tried to find out the problem and not simply make changes because someone said there is a problem. 

I was going to call  up and order Cable internet.  But, I thought about this and It would be really funny to find out that those again with cable are working and my connection would still not work because of a configuration  goof up on my part.

So I am still trying to figure this out. 

The potocol 41 issue seems to be a problem which no one has a straight forward answer.  Unfortunately, because of the lack of communication between the ATT powers that be, one person says no at ATT and then a customer says it's working.  That tells me something is either wrong with my equipment (Configuration issue ) or maybe Protocol 41 is blocked in my area.

I can't get a IPv6 traceroute out past my router.   I can't see any thing past my box.  If there is a way to detect or figure out what is the problem, Please,  I'd like to know.


The only way to tell if AT&T is blocking protocol 41 is for them to tell you if they are or not. Unfortunately I suspect most of their front line support techs have no idea what an IP protocol number is let alone if their systems are blocking any of them. So getting a straight answer from them may be a challenge.


Now that's what I've been saying all along.



Sooo.... I'm new to these forums but not new to networking. I talked to some folks on the commercial side of AT&T and they told me they aren't blocking protocol 41 intentionally. They weren't sure about the consumer side but saw no reason why it would be blocked their either. I can tell you that I have found several articles regarding AT&T DSL and IPv6 and several of them imply poor DSL modems are the bulk of the root causes. I'm on AT&T consumer at home and I'll be setting up my IPv6 tunnel tonight. I can't handle being stuck with the "newbie" certification. :) I'll follow up with my results. For now I'm using a Cisco 1841 ISR with a DSL modem provided by the ISP. If that doesn't work, I'll flip to a WIC-1-ADSL card for my router.

Are you basing your position off what the front level support folks told you? One of the blogs I read mentioned not being able to tracert to What specific symptoms are you seeing?   


Hey.  Nice to hear someone working on the same issue.

Well, the phone call I got was from the ATT "NOC" in Texas.  My nieghbor is a manager at ATT and she is a go getter when it comes to resolving issues with ATT for customers.   

The phone call was like a bad military movie.  "I can't confirm or deny the problems you have and I can not discuss the in depth issue s you are having, but, we are blocking protocol 41.  Case closed.

I also have a Cisco WIC-1ADSL unit that I can put into my router.  The only problem with doing so is I read the unit doesn't support over 4 meg and I have 6.  I also thought I saw the upload speeds were not so hot either.  Please let me know what you find.   If you have a new  unit, maybe you have an HWIC-ADSL2 (something like that) which supports I think up to 24 meg DSL.

specs for that  unit.  http://www.cisco.com/warp/public/146/kits/smb/dsl_strategy/ADSL_WIC_ds.pdf


If AT&T NOC says that they are blocking protocol41, you'll have to take them at their word. Sorry.

Have a look at 6to4, Sixxs, or Gogo6. They use different methods of providing tunnels/connectivity, so one of those might work for you.


Quote from: jrochaHave a look at 6to4, Sixxs, or Gogo6. They use different methods of providing tunnels/connectivity, so one of those might work for you.

6to4 is protocol 41 as well, perhaps you meant Teredo. Most likely it is something in the modem, and if it cannot be changed out, or put into a proper bypass, there isn't much that can be done on our end.


Can I still use HE with those tunnel options?