<div dir="ltr">An ICMP ping is a low-level, very small packet exchange:<div><br></div><div> xymon: Hey, server1</div><div> server1: what??</div><div> xymon: <wanders off><br></div><div><br></div><div>On the other hand, ssh should be setting up and tearing down an encrypted connection, even though it doesn't actually login. I assume there would be multiple packets bouncing back and forth, agreeing on an encryption protocol and swapping keys, or whatever. I'm not very surprised that it takes longer than a ping to complete the connection.<br></div><div><br></div><div>Ralph Mitchell</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Aug 24, 2015 at 11:04 PM, Jeremy Laidman <span dir="ltr"><<a href="mailto:jlaidman@rebel-it.com.au" target="_blank">jlaidman@rebel-it.com.au</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I've noticed the same thing on many of my servers. Without really thinking about it, I just assumed that the xymonnet TCP connection measurements were taking into account (removing) network latency time, and only giving the latency within the server being tested. Thinking about it now, I'm not sure how xymonnet would do this.<div><br></div><div>Yes, I believe xymonping uses ICMP. You can run xymonping directly like:</div><div><br></div><div>sudo -u xymon /usr/lib/xymon/server/bin/xymonping 10.100.2.17</div><div><br></div><div>and see how it compares with the graph, or "ping" or "time telnet 10.100.2.17 22 </dev/null".</div><span class="HOEnZb"><font color="#888888"><div><br></div><div>J</div><div><br></div></font></span></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On 25 August 2015 at 08:02, Shawn Heisey <span dir="ltr"><<a href="mailto:hobbit@elyograg.org" target="_blank">hobbit@elyograg.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Here is a "connection times" graph from Xymon:<br>
<br>
<a href="https://www.dropbox.com/s/voyqnzfnsqaact9/xymonresponsegraph.png?dl=0" rel="noreferrer" target="_blank">https://www.dropbox.com/s/voyqnzfnsqaact9/xymonresponsegraph.png?dl=0</a><br>
<br>
This shows "conn" times in the 40 millisecond rang, and "ssh" times in<br>
the 200 microsecond range.<br>
<br>
What is the source of the "conn" graph? I would have guessed ICMP, but<br>
it doesn't make any sense for a ping to take longer than an ssh<br>
connection, especially not that much longer. This is what I get if I<br>
ping that machine from the xymon server ... it doesn't take anywhere<br>
even CLOSE to 40 milliseconds:<br>
<br>
[root@mcp xymon]# ping palazzo<br>
PING <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17) 56(84) bytes of data.<br>
64 bytes from <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17): icmp_seq=1 ttl=62<br>
time=0.572 ms<br>
64 bytes from <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17): icmp_seq=2 ttl=62<br>
time=0.582 ms<br>
64 bytes from <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17): icmp_seq=3 ttl=62<br>
time=0.573 ms<br>
64 bytes from <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17): icmp_seq=4 ttl=62<br>
time=0.611 ms<br>
64 bytes from <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> (10.100.2.17): icmp_seq=5 ttl=62<br>
time=0.890 ms<br>
^C<br>
--- <a href="http://palazzo.REDACTED.com" rel="noreferrer" target="_blank">palazzo.REDACTED.com</a> ping statistics ---<br>
5 packets transmitted, 5 received, 0% packet loss, time 4003ms<br>
rtt min/avg/max/mdev = 0.572/0.645/0.890/0.126 ms<br>
<br>
Can anyone shed light on this? My server config includes the following<br>
line:<br>
<br>
FPING="xymonping"<br>
<br>
My xymon server is version 4.3.14.<br>
<br>
Thanks,<br>
Shawn<br>
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</blockquote></div><br></div>
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<br></blockquote></div><br></div>