[mdlug] Help with Spotty Internet/Network Problems

[Bruce Smith]

I recently read an article about Gutsy having problems with the DHCP
server in some firewall/routers.  I don't have the URL, but you can
probably google it.

The problem was intermittent, kind of like what you described.  To
verify the problem, try to resolve some hostnames (dig/host/nslookup)
when you are having the problem.  If they don't resolve, then this may
be the cause.

It basically came down to problems with IPV6 in Gutsy, and the
solution was to blacklist the IPV6 kernel modules so they never get
loaded.

Good luck!

 - BS


On 10/26/07, Elisa Gomez <shmi85 at yahoo.com> wrote:
> I'm running Ubuntu (Fiesty and I recently upgraded to
> Gutsy, but the problem's been absolutely the same) and
> I have AT&T DSL and I've been having some problems
> with it for the past six weeks/two months. Every two
> or three weeks, I go through this period of spotty
> coverage, where the connection will work for 30
> minutes or so and then drop back out. If I manually
> shut down the power to the modem and unplug it, the
> connection will usually (but not always) come back up.
> Occasionally I have to restart the computer, which
> sometimes works, but sometimes I also need to shut
> down the modem. The last time this happened, I booted
> up my Windows XP and called tech service -- they had
> me run through a bunch of stupid exercises that
> involved things like clearly my Internet Explorer
> cache, which was pretty much empty to begin with since
> I use Windows once in a blue moon and IE perhaps once
> a year.
>
> It culminated in a technician coming out to check my
> wiring, which turned up absolutely nothing, although
> he replaced the old jack. So I've progressively been
> working backwards -- the phone line is fine. The cable
> from the jack to the modem is fine. The modem (a
> Siemens SpeedStream 4100 ADSL Modem) itself may be
> fine, but I'm not really sure. I have access to a
> whole bunch of different diagnostic tests through the
> modem gui and the tests all green-light, but I'm not
> really sure what the value of those particular modem
> self-tests are. It runs tests on: Ethernet, ADSL, ATM,
> PPPoE, Authentication, IP, and DNS. I can also
> generate a technician readout and a whole bunch of
> other advanced features, but I'm not sure what most of
> it means or how to interpret it. This does show up in
> the technician readout, under PPP Last Connection
> Error:  Your local connection is still busy, please
> wait a few seconds before attempting to connect.
>
> PC-side, I'm using the standard gnome network manager
> programs. I haven't touched anything,
> configuration-wise. The wired connection is set to
> "Roaming Mode" rather than a specific set of
> connection settings. I imagine setting those may help,
> but I don't know what to ask for when I call tech
> support, so I can spend minimal time running through
> irritating cache clearing exercises.
>
> Also, in the interests of full disclosure, this seems
> to always happen to me when I'm downloading torrents.
> This makes me exceptionally paranoid, because they're
> torrents and it's AT&T. Sometimes I will go through a
> period of spotty service and then if I shut down my
> torrent client, my service won't go down anymore
>
> ....
>
> I think I'm just being really paranoid, but it could
> be an effect of transferring a lot of megs of data. I
> don't really know. But know you all know everything I
> know, so any help or advice would be greatly
> appreciated!
>
> ~Elisa