FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Debian > Debian User

 
 
LinkBack Thread Tools
 
Old 07-11-2008, 01:28 AM
Hendrik Boom
 
Default IP forwarding drops out -- more data

On Thu, 05 Jun 2008 10:03:09 -0700, Andrew Sackville-West wrote:

> On Thu, Jun 05, 2008 at 11:11:55AM -0400, hendrik@topoi.pooq.com wrote:
>> I have my network front end running Debian sarge (yet, it's time to
>> upgrade at lest to etch). It's connected to the rest of the net by a
>> DSL line. I've set up port-forwarding to selected machines on my LAN
>> for the convenience of certain games, and bittorrent, and I'd like to
>> use it for some always-on applications.
>>
>> But every now and then, once every week or two, the port-forwarding
>> drops out, and I have to reestablish it by running the same script that
>> gets run on startup.
>>
>> Does anyone have any idea how to track down the problem? I've looked at
>> the system logs and not found anything suspicious. But probably I don't
>> know which logs to look in, or what to look for in them, and it would be
>> as plain as day if I did.
>>
>> If this is a known sarge problem, of course upgrading to etch would be
>> the solution.
>
> just a couple of suggestions.
>
> 1) if you're planning to upgrade, go ahead and do it, the problem may
> just go away. That doesn't really necessarily solve the problem
> though...
>
> 2) does your DSL connection go down from time to time? maybe it's
> dropping out and the system isn't recovering properly.
>
> 3) next time it goes down, instead of just rerunning the network
> scripts, see if you can diagnose the situation a little bit. look at
> the output of
>
> ifconfig
> route
> and maybe get a dump from iptables.
>
> then compare to the state of things when the system is working.
>
> A

OK. It happened again, just now. My son complained that the internet was
down. I ssh'ed to my gateway machine, and ppp0 was up, but had a
suspiciously low packet count (about 150 packets) within a few seconds
it was up to about 250, so it looked as if ppp0 had just come up.

I checked my iptables, and the port forwarding had shut down.
I ran the script is uses to start port-forwarding at boot
time, and it was up and running again in no time.

I went and looked at syslog. It looks very much as if the
ppp0 connection had shut down for a minute or two, and was
automatically restarted. Apparently shutdown of ppp0 was
enough to kill all the port-forwarding instructions
relating to it (which was all of them), and the script did
not get run when the ppp0 connection was reestablished.

So, the question becomes,
(a) how do I ensure that the script gets rerun when ppp0 comes
up
or
(b) How do I keep the forwarding from being dropped when ppp0 goes down?

-- hendrik


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
 
Old 07-11-2008, 07:15 AM
Alex Samad
 
Default IP forwarding drops out -- more data

On Fri, Jul 11, 2008 at 01:28:19AM +0000, Hendrik Boom wrote:
> On Thu, 05 Jun 2008 10:03:09 -0700, Andrew Sackville-West wrote:
>
> > On Thu, Jun 05, 2008 at 11:11:55AM -0400, hendrik@topoi.pooq.com wrote:
> >> I have my network front end running Debian sarge (yet, it's time to
> >> upgrade at lest to etch). It's connected to the rest of the net by a
> >> DSL line. I've set up port-forwarding to selected machines on my LAN
> >> for the convenience of certain games, and bittorrent, and I'd like to
> >> use it for some always-on applications.
> >>
> >> But every now and then, once every week or two, the port-forwarding
> >> drops out, and I have to reestablish it by running the same script that
> >> gets run on startup.
> >>
> >> Does anyone have any idea how to track down the problem? I've looked at
> >> the system logs and not found anything suspicious. But probably I don't
> >> know which logs to look in, or what to look for in them, and it would be
> >> as plain as day if I did.
> >>
> >> If this is a known sarge problem, of course upgrading to etch would be
> >> the solution.
> >
> > just a couple of suggestions.
> >
> > 1) if you're planning to upgrade, go ahead and do it, the problem may
> > just go away. That doesn't really necessarily solve the problem
> > though...
> >
> > 2) does your DSL connection go down from time to time? maybe it's
> > dropping out and the system isn't recovering properly.
> >
> > 3) next time it goes down, instead of just rerunning the network
> > scripts, see if you can diagnose the situation a little bit. look at
> > the output of
> >
> > ifconfig
> > route
> > and maybe get a dump from iptables.
> >
> > then compare to the state of things when the system is working.

have a look at /etc/ppp/ip-up.d/

> >
> > A
>
> OK. It happened again, just now. My son complained that the internet was
> down. I ssh'ed to my gateway machine, and ppp0 was up, but had a
> suspiciously low packet count (about 150 packets) within a few seconds
> it was up to about 250, so it looked as if ppp0 had just come up.
>
> I checked my iptables, and the port forwarding had shut down.
> I ran the script is uses to start port-forwarding at boot
> time, and it was up and running again in no time.
>
> I went and looked at syslog. It looks very much as if the
> ppp0 connection had shut down for a minute or two, and was
> automatically restarted. Apparently shutdown of ppp0 was
> enough to kill all the port-forwarding instructions
> relating to it (which was all of them), and the script did
> not get run when the ppp0 connection was reestablished.
>
> So, the question becomes,
> (a) how do I ensure that the script gets rerun when ppp0 comes
> up
> or
> (b) How do I keep the forwarding from being dropped when ppp0 goes down?
>
> -- hendrik
>
>
> --
> To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
> with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
>
>

--
"Our enemies are innovative and resourceful, and so are we. They never stop thinking about new ways to harm our country and our people, and neither do we."

- George W. Bush
08/05/2004
Washington, DC
 
Old 07-13-2008, 03:19 AM
Hendrik Boom
 
Default IP forwarding drops out -- more data

On Fri, 11 Jul 2008 17:15:53 +1000, Alex Samad wrote:

>
> have a look at /etc/ppp/ip-up.d/

Thanks. I linked my port-forwarding start script to /etc/sbin/ipmasq.
It should stay up now if 00ipmasq actually gets executed when ppp0 comes up.


-- hendrik


--
To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
 

Thread Tools




All times are GMT. The time now is 12:27 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org