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--- faq:network_troubleshooting [2007/06/11 18:11 (17 years ago)] – created kevin
+++ faq:network_troubleshooting [2019/11/20 16:35 (4 years ago)] – 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 trouble shooting.
+  * Ask your IT to review information from a network analyzer such as wireshare or similar tool.
 ===== Things to consider when things go wrong =====
@@ Line 12: / Line 13: @@
   * Are there any patches available for the server hardware?  Firmware such as RAID card, network card, BIOS?
   * Could line voltage be an issue?  Any large motors, compressors or welding devices nearby?  You may want to consider some power conditioning.
-  * Last resort mainly due to the expertise level required and time involved is install and review information from a network analyzer.
+  * Check for pending Windows updates on all workstations / servers involved.  Strange things can occur when these updates have not been applied.
+  * Check power settings.  We have seeing OS updates reset power settings
+  * 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 can fail and mice will eat working ones and they will still sort of work)
+  * Poorly routed cables (Don’t run parallel with power wires as magnetic fields will cause corruption)
+  * Network cards that randomly fail but work most of the time (Poorly crafted operating system drivers can cause this type of issue as well)
+  * Other environmental considerations (Newly installed welders, air conditioners, or other power hungry devices in the same building (even outside the company) can cause power brown outs which can cause pieces of equipment to fail during startup of the power hungry device)  Install a UPS and if it is beeping every few minutes, you may have a power issue.
+  * 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 trouble shoot 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