[OPLINTECH] EXTERNAL: Intermittent network issues

[Ed Liddle]

Dan,
How do you have the IP address setup on the ubuntu machine that you are having problems with?
We had a physical machine running ubuntu. I was using a DHCP reservation to assign it an IP address based on the MAC address of the NIC.
It would work for a while then we would have trouble accessing it on the network.
What I discovered is when we had trouble, the IP address and MAC address changed on the computer. When we had trouble, I would log into the ubuntu server and check the ip address on the command line. It would show a different IP address. I would then look up the new IP address on the windows DHCP server and notice that the MAC address was different than the DHCP reservation I made for it.
What I ended up doing was configuring the Ubuntu server to use a static IP address, which was a different process than I was used to.
This article explains how to configure a static IP address by editing a yaml configuration file.
https://www.osradar.com/set-a-static-ip-address-ubuntu-20-04/

When you experience trouble with it, log into the ubuntu server and check to see what IP address it is getting. If it pulls a different IP address from the DHCP server, you will be able to ping other machines on the LAN and get a response since it does have an IP address. Anything trying to access the server from the network won't be able to find it if the IP address changed.

I hope this helps.

-Ed Liddle
Marysville Public Library
http://marysvillelib.org
________________________________
From: OPLINTECH <oplintech-bounces at lists.oplin.org> on behalf of Danny Will via OPLINTECH <oplintech at lists.oplin.org>
Sent: Thursday, March 17, 2022 12:42 PM
To: 'OPLINTECH (OPLINTECH at lists.oplin.org)' <OPLINTECH at lists.oplin.org>
Subject: EXTERNAL: Intermittent network issues


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Hi all,

     It’s not often that I’m stumped but…



I have a windows 2019 server with 2 virtual machines running Ubuntu Linux server (no GUI installed). Both are 20.0.4.3 but, that really isn’t the important part. Both are running websites. One is a copy of the Meeting Room Booking System and it runs perfect. The other is a slightly modified copy of Omeka database system that we use as our local history site. Cataloging newspapers, High School yearbooks, Photographs, & just about anything else that is historically worthy of keeping. While it is getting kind of large, it works fine EXCEPT…



>From time to time, & without any indication of why, this site cannot be reached. I have tried the WAN address by both FQDN & IP address. I have tried the LAN address (10.66.76.24) to no avail. If I log onto the virtual machine, I can ping the internal DNS server & any external address (google.com, etc.).

This comes and goes without rhyme or reason. At this point I am ready to pull out what little hair I have out.



I thought at 1st, that the firewall was the issue, so I changed things around to by-pass the usual firewall. Worked for a little while then it was down again (worked for maybe 2 or 3 hours, just enough time that I left for home just to hear a short time later we were getting calls about it being down again).  So it was not the firewall. I made a small change to the NIC settings on the server. It worked fine after that…for 20 minutes back down.



TIA



Dan Will

Meigs County District Public Library

Technology Supervisor

danwill at meigslibrary.org<mailto:danwill at meigslibrary.org>

740.992.5813


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