16 Replies Latest reply on Aug 26, 2016 8:43 AM by momarm

    Cisco Switch keeps going 'down'

    momarm

      Hi guys. Very new to networking. One of our Cisco switch recently started to go down:
      CiscoSG200***************** has stopped responding (Request Timed Out)

       

      I would reset it and after about 15 or 20 minutes it would start responding. When this happens I dont see any red lights or anything, physically it looks fine. I've cleaned our DNS. Could someone advise how should I go about troubleshooting this and anyway to check if this may be a hardware issue perhaps?

        • Re: Cisco Switch keeps going 'down'
          d09h

          Packet capture from poller.  SPAN management interface of switch and capture that too.  Review each capture for poll from SolarWinds and response from switch.

          • Re: Cisco Switch keeps going 'down'
            jaybone

            Is the switch passing other traffic normally while it's "down?"  I.e. is it just the management interface that's not accessible?

            Assuming you have some visibility to the switch via console while it's down, what do the onboard logs say?

              • Re: Cisco Switch keeps going 'down'
                momarm

                So everything on it stops responding after a few seconds it shows down. I have not been able to extract logs which ill be doing today. I'll report back as soon as i have something. Also I checked solarwinds logs for this during the weekend, it would atleast once a day go down and reconnect after a few hours, and one time after 30 minutes on its own.
                FYI its a Cisco SG220 50-Port Gigabit Smart Plus Switch

                  • Re: Cisco Switch keeps going 'down'
                    rschroeder

                    What do the switch's log files show?  Is it rebooting, or showing errors?

                     

                    Are you monitoring its uplink port(s) with NPM?  If so, you may be able to identify bandwidth issues that could be associated with a broadcast storm.

                     

                    Similarly, if you're monitoring all of its access ports with NPM, it can show you high utilization, high errors, high discards, etc., which may lead you to discovering one or more devices that could be causing this issue.

                     

                    Remember that failure to respond to ICMP doesn't necessarily indicate the device is actually disconnected or powered off/rebooting.  ICMP is a second class citizen to TCP data, and if a switch has few resources available, it will not respond to pings.

                     

                    Similarly, if the uplink bandwidth availability is low (such as across a T1 or small DSL WAN link), one or more users streaming audio/video can cause havoc for all users of the switch.

                      • Re: Cisco Switch keeps going 'down'
                        momarm

                        So i still have not been able to get the logs(cant find a console cable :/ ). But it does not reboot nor does it turn off, but the sequence is first I see it go down on solarwinds, all the lights on the switch are green though, all ports etc, but they loose connection, and im not able to ping the switch or anything that on it. Also I have moved everything on it to a procurve and no issues. Note also that we mostly had printers so only 25% of the ports were being used. Now that ive moved everything off it check this out:

                        TIME OF EVENTMESSAGE
                        8/23/2016 7:47 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)
                        8/23/2016 6:09 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)
                        8/23/2016 2:46 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)
                        8/23/2016 2:04 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)
                        8/23/2016 1:52 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)
                        8/23/2016 1:08 AMCiscoSG200-50-NY-Floor10-IDF1 has stopped responding (Host Unreachable)


                        Empty switch.

                  • Re: Cisco Switch keeps going 'down'
                    CourtesyIT

                    How is your routing? Loops?

                    It is to a Loopback, Vlan or Physical Interface?

                    How are you monitoring? ICMP or SNMP?

                    • Re: Cisco Switch keeps going 'down'
                      CourtesyIT

                      I would recommend get a support contract, because you do not want to miss the updates and upgrades. 

                      2 of 2 people found this helpful
                      • Re: Cisco Switch keeps going 'down'
                        d09h

                        Even if you don't procure a suitable console cable for these efforts, you may wish you had if another issue with that type of switch arises.  SNMP queries wouldn't have to be the only visibility into your issue.  If you knew the pinout, you could probably even modify a console cable you have lying around.

                         

                        Your next issue might have more urgency, and console access could expedite your solution.  And with more knowledge into the nature of the root problem, you could determine what (if any) additional polling would have helped.

                        1 of 1 people found this helpful