Re: Ping/etc. Problems -- MIDRANGE-L

The question was asked how I determined what was happening in my case.
I determined what was occurring by the results I saw with a default
wait interval (1 second) and an increased wait interval (10 seconds).

With the default wait interval, every other ping was responding, and
in all cases ping 1 was never verified.  And pings 2, 4, 6 etc.. were
all reported as under 1000ms (one second).

With the 10 second wait interval, all pings were responding, and
in all cases were over 1000ms.  The only explanation was that the
10second wait interval was showing the real ping and pong times
as it was waiting for the response and all were responded to.  So
the default wait time of 1 second was reporting incorrect responses.
And since the pongs were always taking longer than 1 second, than the
reported pongs must be from the previous ping.

This was ran in NT 4.0 workstation.  Nowhere did I see a duplicate
pong message.  Now, I could be totally wrong, but this is the simplest
explanation that matches the data.

Regards,

Jim Langston

I have but yet begun to type!

Date: Fri, 13 Jul 2001 17:36:15 -0400
From: Neil Palmer <neilp@dpslink.com>
Subject: Ping/etc. Problems

When you get a reply after the wait interval (default 1 second) the 400 
will identify them as (Duplicate) as in this example:

ping someplace
Verifying connection to host system someplace at address 999.999.0.240.  
No response from host within 1 seconds for connection verification 1. 
No response from host within 1 seconds for connection verification 1.
No response from host within 1 seconds for connection verification 2.
PING reply 1 from 999.999.0.240 took 2142 ms. 256 bytes. TTL 236. 
  (Duplicate) 
<SNIP>

thomas@inorbit.com
Sent by: owner-midrange-l@midrange.com
2001/07/13 17:04
Please respond to MIDRANGE-L

 
        To:     MIDRANGE-L@midrange.com
        cc: 
        Subject:        Re: MIDRANGE-L Digest V4 #735


Jim:

<SNIP>

Although I've seen timing issues as you describe, I've never seen the 
behavior that you saw. I had somewhere gotten the understanding that each 
ping packet had a unique (sequential?) identifier to ensure that ping 2 
would not respond to the pong from ping 1. But your experience calls that 
into question. How did you determine what was happening in your case?

Tom Liotta

On Thu, 12 July 2001, Jim Langston wrote:

> 
<SNIP> 
> So why did I initially see every other ping?  The timing.  Pings wait 1 
second as
> the default before timing out.  So, it would send a ping, wait one 
second for a
> response, state it timed out, send the second ping, wait... and receive 
the 
> response from the first ping!  It would report this as the second ping, 
then it
> would send the third ping, time out, send the 4th ping, and receive the 
response
> to the third ping...
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