Subject: SLIP problems.
To: current-users <>
From: Burgess, David (TSgt) ~U <BurgessD@J64.STRATCOM.AF.MIL>
List: current-users
Date: 02/02/1994 09:14:00
Ever since Last Thursday, I have not been able to reliably use my SLIP 
bridge.  It will work for about 10 seconds and then it hangs the bridge 
router connecting me to the net.  The problem has just cropped up, and I am 
trying to find out from as many sources as I can what might be the problem.

There are a couple of symptoms.

1.  The bridge will route packets to me, sort of.  Many will come in with 1 
to 3 bytes missing (according to tcpdump).  Others will just be ignored.  I 
am getting lots of packets dropped by the kernel.

  A good example is my newsfeed.  It uses nntpsend to route the news to me. 
 Every five minutes, it tries to connect to my host.  Once the host is back 
on line, it will try to synch and send the news that has been accumulating 
for me.  Right now, it sends me messages, and within a few msecs, my system 
sends out the response.  The machine at the other end might get one in a 
thousand.  It is the last time that the connection makes sense.  Note that 
nameserver requests on the .domain socket are completely ignored.

2.  The bridge will occasionally route a packet out for me to the intended 
recipient.  It works more reliably early on in the connection.

3.  Ping to the bridge stops working.  Once I get the connection 
established, the bridge either gets completely over-whelmed by bad packets 
and hangs, or just craps out.

The fault could lie nearly anywhere.  I tend to think that it might be 
NetBSD's fault, since it was working before my last major sup and rebuild. 
 Of course, if it WERE NetBSD, I would expect to see a lot more questions 
about it (although if people can't connect because their SLIP has stopped 
working...  Kind of the sound of one hand clapping.)

Has anything in the networking code (specifically the SLIP code) changed 
between the 24th (my last good rebuild) and the 27th (or thereabouts?).

Another thing that has started happening recently is that my lpa driver has 
started dropping characters.  Since one of the trouble indicators (above) is 
that 1 to 3 characters are being missing out of the incoming IP packets, I 
am wondering if these could possible be related.

Any help you could be would be greatly appreciated...