Subject: Re: Odd network trouble
To: Prak <prak@WPI.EDU>
From: Christopher P. Gill <cpg@scs.howard.edu>
List: port-mac68k
Date: 02/25/2000 18:12:56
On Wed, 23 Feb 2000, Prak wrote:

> A IIci running NetBSD 1.4.1 stops responding to network requests from
> machines outside of my internal network after about two hours without
> network activity.  When this happens if I ping it or something, from my
> other machine, which sits right next to it on the network, the IIci will
> begin respond to the outside requests as well.  (The other machine is also
> responding happily to outside network requests all this while.)

I occasionally saw this kind of trouble on my system (Quadra 800, NetBSD
1.4 GENERIC kernel, 500+520/40; 80MB swap).  Basically the machine
connected from it's AAUI interface to my hub, which had its uplink port
connected to my ADSL modem/bridge.  I had an extra NIC that I had started
to get working with ipnat, which was also connected to the hub, but with a
'private' IP address, and that interface had nothing active but AppleTalk.
The machine would, after a couple days or somewhat longer, be unreachable
from outside (no ping response, etc.). I'd telnet in from another machine
right next to it once I got home, and after a really long delay, it would
usually connect, and the machine would 'recover'.  I'm not sure, but once
or twice it might even have recovered on its own.  Usually I'd just start
an outgoing connection from the console, and the problem would go away.

> I have a SDSL modem.  The modem is connected to the uplink port of the hub
> which is then connected to the IIci and a powermac.  The powermac is
> running System 8.5 and the IIci is running a standard install of
> NetBSD.  (With the addition of Bind 8, Apache, and perl)  Both machines
> have real static IPs.  (ie. No IP masq)  More detailed hardware specs are
> provided at the bottom.
> 
> I am not sure what this is a problem with: NetBSD, the modem, hub, NIC, or
> IIci all seem about equally suspect.  Poking around the IIci while it is
> having trouble failed to reveal anything suspicious; The modem has worked
> fine for every other machine; I have tried switching around the ports on
> the hub along with changing all the wires;  Hardware wise nothing looks
> burnt and the IIci and NIC are fully supported;  I have even tried doing a
> completely clean install on the off chance that might help.  Nothing has
> changed.  Not sure if there is anything else I could/should be doing.

I haven't noticed my machine exhibiting the problem since I started
running the seti@home and/or rc5 clients.  The regular network access
probably prevents the TCP/IP 'staleness' from setting in. 

> If anyone might happen to have any clues as to why this might be happening
> or even what I might need to look into, it would be much
> appreciated.  Thank you.
> 
> Hardware Specs:
> 
> Mac IIci
>  - Mac OS 7.5.3 / NetBSD 1.4.1
>  - 32 megs ram
>  - 800 meg Quantum Trailblazer
>    * 32 megs swap
>    * 750 megs /root+/usr
>  - Mac IIci Cache Card
>  - Asante MacCon-i NuBus Card
>  
> Network
>  - Asante FriendlyNet 8-port Hub
>  - Efficient Networks SpeedStream 5250 SDSL Modem
>  - DSL Provider - Speakeasy
> 
> -prak
> "And when the trial continued, they asked Prak a most unfortunate thing.
> They asked him -- to tell the Truth, the Whole Truth and Nothing but the
> Truth.  Only don't you see?  They had given him too much of the drug!"

/*======================================================================
"Don't die wondering..."                http://www.cldc.howard.edu/~cpg
                                              email: cpg@scs.howard.edu
chris out-              Christopher P. Gill
  peace.        C.L.D.C. Senior System Operator (Ret.)
======================================================================*/