Differences

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--- faq:network_troubleshooting [2020/03/18 11:23 (4 years ago)] – kevin
+++ faq:network_troubleshooting [2020/03/30 11:55 (4 years ago)] – [Things to consider when things go wrong] kevin
@@ Line 5: / Line 5: @@
   * Purchase quality network switches, hardware, use professional cabling and patch panels.
   * Buy patch cables instead of building your own.  For the cost, it is not worth the dollar savings.  A bad patch cable can cause many hours of troubleshooting.
-  * Ask your IT professional to review information from a network analyzer such as [[https://www.wireshark.org/|Wireshark]] or similar networking tool.
+  * Ask your IT professional to review information from a network analyzer such as [[http://www.pingplotter.com/|PingPlotter]], [[https://www.wireshark.org/|Wireshark]] or similar networking tool.
 ===== Things to consider when things go wrong =====
   * Check the server event log for any message or hints towards what may be failing.
   * How old is the hardware?  Has it run successfully before?
-  * What is new?  Has anyone brought a device in from home or plugged something in?
+  * What is new?  Has anyone brought a device or switch in from home or plugged something in?
   * Could the server drive or controller be failing?  Is it a single drive or in a RAID configuration?
   * Are there any patches available for the server hardware?  Firmware such as RAID card, network card, BIOS?
@@ Line 16: / Line 16: @@
   * Check for pending Windows updates on all workstations/servers involved.  Strange things can occur when updates have not been applied a server degrades into a "reboot pending" state.
   * Check settings for power saving options and disable.  We have seeing OS updates reset power-saving settings.
-  * Bad or failing ports on switches that are not consistent (Even new ones can fail)
+  * Check for bad or failing ports on switches that are not consistent (Even new ones can fail)
   * Ports auto-detecting incorrectly (ie: 10Mb detected on the switch when the server is transmitting at 100Mb)
   * Incorrectly crimped cables (Even store-bought cables can fail and mice will eat working ones and they will still operate some of the time)
@@ Line 24: / Line 24: @@
   * Is there a duplicate IP address that conflicts with the server or workstation?  You should get a message about this but the message could be presenting at the user workstation level and taking communication to the server off the network.  To troubleshoot review your ARP table such as at cmd prompt with ARP – A will show the physical NIC addresses which you would want to confirm are correct against the NIC of the server.
   * Is there another DHPC server conflicting with yours?  You would have to look for DHCP traffic on port 68 on your switch to find out where it is plugged in.  We have seen some network technicians choose to configure the switch to throw away DHCP packets from any other source than your DHCP server as it is a common gotcha and is really hard to find
+  * Are you using Voice over IP phones on the same network as your data?  The best networking practice would be to configure a separate VLAN for phone traffic to allow the data network to communicate without competing with packet priority over voice data.
+  * Is there any third-party software installed such as State or Provincial level tools that could impact VPN or network access?
+  * Have you swapped internet providers and left old DNS information hardcoded on workstations?  This can be overlooked and can cause 30-second timeout delays while DNS fails over to a working DNS server.  Due to the round-robin and caching nature of DNS, System Five will work sometimes and have a long delay at othertimes.