using a mac with linux and filepro

[Fairlight]

In the relative spacial/temporal region of Sat, Jun 16, 2007 at 02:48:23AM
-0400, Brian K. White achieved the spontaneous generation of the following:
> These days we are having a rather common problem with end users
> isp's idling out tcp sessions after only a few minutes. This is
> happening in the ISP outside of anyones control. It's been demonstrated
> empirically and simply that it's not some setting in an ones dsl modem
> or router. Some isp's just plain do it for all of an entire class of
> connection. Verizon dsl being the biggest culprit around here but not the
> only one. Optimum cable does it after 1.5 hours too but thats at least
> sufferable.  In neither case am I talking about the entire et connection
> btw. I mean individual tcp sessions, when idle for a few minutes for dsl,
> or 1.5 hours for cable, are being cut by the isp, having nothing to do
> with other tcp sessions or the connection as a whole.  FacetWin, neither
> the sever nor the client does any kind of keep-alive heartbeating or
> pinging. And they are both proprietary and neither can be used without
> the other.  So, end users who log in from verizon dsl connections, if
> they use facetwin, they get continuously ungracefully blown out of
> programs they are in. The locked records and headless processes on the
> servers... ugh...  Meanwhile putty has a simple little common setting
> that many many other telnet/ssh clients have that sends a null packet to
> the server every so many seconds.  And/or from the other end, both telnet
> and ssh servers can send heartbeat "are you still there?" queries to
> clients, who respond if they are there.  Either of those forms of traffic
> keeps the tcp session from being idle and can be configured to happen
> often enough so that verizon dsl never drops the session unless the user
> wants to or when its ok to for some other reason like their pc shut
> off. So, even if putty didn't happen to have that feature, as an open
> source user:

I think I know what's quite possibly causing that.

When I got DSL from BellSouth like 3 years back, I had bridged DSL.  The
IP layer had no concept of the underlying anything.  Everything was
entirely transparent.

Now, DSL is configured in both bridged and PPPoE connections to idle out
and reconnect.  They do this so that if you don't pay, you're
automatically cut off at the next disconnect.  Ours happens to be on
about a 48hr or 72hr cycle (I forget which they're doing.  It could be
tuned higher or far lower, however.

Now one thing I noticed was that certain protocols are REALLY dodgy about
this.  I noticed ssh in particular, if I actually lost sync, I could have
connections up to IRC or whatever, and as long as I recovered sync by the
end of the 2min timeout window on a connection, I regained that
connection for most TCP connections.  SSH, however, -never- survived a
DSL desync.  If that route goes away, *poof*, you are -gone-.  This is
both PuTTY and openssh.  Doesn't matter which.  Any versions...I've run
into it across more than a few versions of each.

Now when I was on bridged, that timeout based disconnect was transparent,
and the IP layer did NOT KNOW that the route went away, because it was
totally, completely 100% transparent.  Three days or so after I was
forced to switch to PPPoE, I started noticing disconnects on SSH whenever
the PPPoE received a PADT packet and was forced to re-login.  Didn't
matter that the route was the same, nor that it was the same IP#
(static), whatever.  If PPPoE was reset, ssh drops, period, the end.

I'm suspecting that's what you're running into.  If you have access to
the router logs and can throw it to debug mode, look for PADT packets
received at the time your TCP connections die and see if it correlates.
If it does, there's your culprit.

And as a matter of some much-needed levity in this thread, you mentioned
Apache, and LAMP sprang to mind.  I realised that the equivalent on Windows
with IIS would be WIMP. :)

mark->
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