Wireshark-users: Re: [Wireshark-users] Using Wireshark for a DSL "link no surf" problem
From: Kok-Yong Tan <ktan@xxxxxxxxxxxxxxxxxxx>
Date: Tue, 17 Jun 2014 19:10:03 -0700
According to a more helpful member of the ISP's tech support staff, he tells me that he *CAN* see the layer 2 link from his end.  Just that there's no layer 3 traffic flowing across it, just the occasional layer 2 "keep alive" pulses.  

Also, I can connect directly into the DSL modem.  With reference to this user manual for my DSL modem 


I have solid green lights for the Power, LAN and DSL LEDs but a totally dark Internet LED (which I think mirrors exactly what the helpful tech support rep is saying).  In the diagnostic page of the DSL modem, it says that "ATM OAM segment ping" and "ATM OAM end to end ping" fails.  Also, PPPoE server session and authentication to server fails.

I have screenshots of the various webpages on the DSL modem with more info if it's of any help (I don't know if it can be posted on this mailing list--some mailing lists prohibit attachments).
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On Jun 17, 2014, at 16:31 , Pedro Tumusok <pedro.tumusok@xxxxxxxxx> wrote:

Usually the CPE gives you some data about the physical link that can be used to figure out what the issue is.
Are you sure there is L2 connectivity?

Pedro


On Tue, Jun 17, 2014 at 11:53 PM, Kok-Yong Tan <ktan@xxxxxxxxxxxxxxxxxxx> wrote:

> On Jun 17, 2014, at 14:28, Jaap Keuter <jaap.keuter@xxxxxxxxx> wrote:
>
>> On 06/17/2014 08:42 PM, Kok-Yong Tan wrote:
>> Is it possible to use Wireshark to troubleshoot a DSL "link no surf" problem?  The ISP insists it's a CPE issue but the problem only started after their Tier 1 tech monkeyed with the DSLAM and/or the CPE (remotely) in some manner.  I find it suspicious that the problem was intermittent packet loss until they tinkered, whereupon the problem became a "link no surf" issue (i.e., there's Layer 2 connectivity but zero Layer 3 traffic passing).
>
> Depends on what you can trace in the CPE, as in, how close to the DSL interface.
> Otherwise you'll need capture hardware on the DSL....
>
> Good luck,
> Jaap
>

I can get up to the DSL modem itself.  In hindsight, I'm thinking this isn't going to be of much use and the only way to debug this is with capture hardware on the DSL side as you suggested.  Drat.
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Best regards / Mvh
Jan Pedro Tumusok

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