<div dir="ltr">I'm completely unfamiliar with your network, with the SDA client, its server, etc. But in a scenario like this, I'd probably use Wireshark to find out exactly what's going on between the client, the server, its DNS lookups, etc. That will likely help quite a bit in determining exactly where to look for the source of the problem. You'll be able to compare a normal working condition against when the problem is happening. If the client is making normal requests, but the server isn't responding in a timely manner or with the normal responses, then you know to focus more on the server side. If DNS isn't resolving with the expected addresses, you'll know to look into DNS, etc. etc.<div><br></div><div>Watching how the network operates at a packet level is an immensely useful skill to explore, if you haven't done that before. This could give you a good opportunity to add that skill to your toolbox, if you haven't already done so!</div><div><br></div><div>2 cents.</div><div><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div>______________________________<br><b>Chad Neeper</b><br><font size="1">Senior Systems Engineer</font><br><br><b>Level 9 Networks</b><br><font size="1">740-548-8070 (voice)<br>866-214-6607 (fax)</font><br><br><font size="1"><i>Full IT/Computer consulting services -- Specialized in public libraries</i></font><br></div></div></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Jun 27, 2023 at 11:57 AM Phil Shirley via OPLINTECH <<a href="mailto:oplintech@lists.oplin.org">oplintech@lists.oplin.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="msg-6895799939726679586">
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<p class="MsoNormal">Hi,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Something on our local network (or some software on our PCs?) is giving us problems. Any idea where I should look?<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">We continue to have occasional problems with “JAR file not found” when starting the SDA (Sierra staff client) – this is apparently a problem on our network, possibly related to the large number of connections the SDA makes at startup to
check each of its 80 or so JAR files against the version on the server (this might look a little like a DDoS). But today something different happened.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">We had a different problem this morning with SDA. Existing connections to the server continued to work (one person logged onto Sierra a few minutes before), and we could telnet to the port that this program uses and use the classic catalog
and Encore, but from about 9:00 to about 9:45 when we tried to start the SDA, it closed after a few seconds and gave no error message. This happened on at least four different workstations. I think that one workstation was able to connect during this time.
After about 9:45 I haven’t been able to get the problem to happen again.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Any idea what might cause this? DNS was working. The person at III support didn’t see anything wrong. He advised me to delete the contents of the jarcache folder and then try loading SDA; it did not populate that folder at all, which is
the first thing that happens when SDA connects to the server.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I’m waiting for a call back from our firewall vendor to see if they can see anything on our firewall.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I checked the switches that the staff use and found that the DDOS protection feature is disabled.
<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Phil<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal" style="line-height:115%"><b><span style="font-family:Arial,sans-serif">Phil Shirley</span></b><span style="font-size:10pt;line-height:115%;font-family:Arial,sans-serif"><br>
<i>IT Manager</i><br>
<b>Cuyahoga Falls Library</b></span><span style="font-size:9pt;line-height:115%;font-family:Arial,sans-serif">
</span><span style="font-size:10pt;line-height:115%;font-family:Arial,sans-serif"><br>
p. 330.928.2117 x109 e. <a href="mailto:pshirley@fallslibrary.org" target="_blank">pshirley@fallslibrary.org</a><br>
<b>www. <a href="http://fallslibrary.org" target="_blank">fallslibrary.org</a> a. 2015 Third Street, Cuyahoga Falls, OH 44221</b><u></u><u></u></span></p>
<p class="MsoNormal"><a href="https://www.facebook.com/fallslibrary/" target="_blank"><span style="font-size:10pt;font-family:Arial,sans-serif;color:windowtext;text-decoration:none"><img border="0" width="24" height="24" style="width: 0.25in; height: 0.25in;" id="m_-6895799939726679586Picture_x0020_5" src="cid:188fddd81df4cff311"></span></a><span>
</span><span style="font-size:10pt;font-family:Arial,sans-serif"> </span><a href="https://twitter.com/FallsLibrary" target="_blank"><span style="font-size:10pt;font-family:Arial,sans-serif;color:windowtext;text-decoration:none"><img border="0" width="24" height="24" style="width: 0.25in; height: 0.25in;" id="m_-6895799939726679586Picture_x0020_6" src="cid:188fddd81df5b16b22"></span></a><span style="font-size:10pt;font-family:Arial,sans-serif"> </span><a href="https://www.instagram.com/fallslibrary/" target="_blank"><span style="font-size:10pt;font-family:Arial,sans-serif;color:windowtext;text-decoration:none"><img border="0" width="24" height="24" style="width: 0.25in; height: 0.25in;" id="m_-6895799939726679586Picture_x0020_4" src="cid:188fddd81df692e333"></span></a><span><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
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