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SG350-28P Some ports dropping on/off

Hi Everyone,

I have a SG350-28P switch acting all haywire. The switch has 1 wireless link and 6 IP Cameras (PoE) connected to it.  The ports where the IP cameras are connected; are dropping randomly (frequently). Port1 (where the wireless link is connected) drops off sometimes but not as frequently as the other ports. I had a computer connects and run a continuous ping test and that seems to be working fine (not dropping) Any idea what could be the cause?


2147483591        2019-Jun-18 04:46:05     Warning               %STP-W-PORTSTATUS: gi5: STP status Forwarding  

2147483592        2019-Jun-18 04:46:05     Warning               %CDP-W-VOICE_VLAN_MISMATCH: Voice VLAN mismatch detected on interface gi1.  

2147483593        2019-Jun-18 04:46:04     Warning               %STP-W-PORTSTATUS: gi4: STP status Forwarding  

2147483594        2019-Jun-18 04:46:04     Warning               %STP-W-PORTSTATUS: gi8: STP status Forwarding  

2147483595        2019-Jun-18 04:46:03     Warning               %STP-W-PORTSTATUS: gi2: STP status Forwarding  

2147483596        2019-Jun-18 04:46:03     Warning               %STP-W-PORTSTATUS: gi1: STP status Forwarding  

2147483597        2019-Jun-18 04:46:03     Warning               %STP-W-PORTSTATUS: gi3: STP status Forwarding  

2147483598        2019-Jun-18 04:46:03     Informational     %LINK-I-Up:  Vlan 800  

2147483599        2019-Jun-18 04:46:03     Informational     %LINK-I-Up:  gi1  

2147483600        2019-Jun-18 04:46:00     Informational     %LINK-I-Up:  gi5  

2147483601        2019-Jun-18 04:46:00     Informational     %LINK-I-Up:  gi4  

2147483602        2019-Jun-18 04:45:59     Informational     %LINK-I-Up:  gi8  

2147483603        2019-Jun-18 04:45:59     Informational     %LINK-I-Up:  gi2  

2147483604        2019-Jun-18 04:45:58     Informational     %LINK-I-Up:  gi3  

2147483605        2019-Jun-18 04:45:57     Warning               %STP-W-PORTSTATUS: gi23: STP status Forwarding  

2147483606        2019-Jun-18 04:45:52     Informational     %LINK-I-Up:  gi23  

2147483607        2019-Jun-18 04:45:51     Warning               %STP-W-PORTSTATUS: gi6: STP status Forwarding  

2147483608        2019-Jun-18 04:45:47     Informational     %LINK-I-Up:  Vlan 1  

2147483609        2019-Jun-18 04:45:47     Informational     %LINK-I-Up:  gi6  

2147483610        2019-Jun-18 04:45:47     Informational     %LINK-I-Up:  loopback1  

2147483611        2019-Jun-18 04:45:47     Warning               %LINK-W-Down:  gi28  

2147483612        2019-Jun-18 04:45:47     Warning               %LINK-W-Down:  gi27  

2147483613        2019-Jun-18 04:45:46     Warning               %LINK-W-Down:  gi26  

VIP Advisor


      - Review the port configuration(s) , make sure they are in host-mode and or being set as access-ports.


Thank for your reply Marce1000. I will have  a look at the switch to confirm if the ports re set up as access. I did a reboot from the console and that seems to have resolved it. No dropping out yet. 


I see similar behavior on my C1000L switches. All ports are confirmed access ports and the end connection are to work stations that stay online always unless rebooting to apply updates. So they are ports that Id expect 99.0% uptime on but are not. No issues are reported as a result but trying to understand what or why this occurs?

Hi MMSIT, the switch has been working fine since the reboot. I will port the results if I manage to find something else. Thank you for your reply. 


Hi everyone,

So after 2 weeks or so the switch started to do act up. I had another SG350 8 port switch and I installed it there and disable STP. everything was good until I plug in the IP cameras. as soon as I plug in the cameras the new switch starts behaving the same way. Only common denominator I can think of is PoE. there's 1 more camera connected with a power injecter and that (port) works fine. Below is the log entries


147483604 2019-Jun-18 04:46:34 Informational %NT_poe-I-PowerNegStatus: Port gi5 power negotiation moved to expire state, power protocol and allocation will remain at 13W (LLDP) until port down/up cycle
2147483605 2019-Jun-18 04:46:34 Warning %LINK-W-Down: gi5
2147483606 2019-Jun-18 04:46:34 Informational %NT_poe-I-PowerNegStatus: Port gi3 power negotiation moved to expire state, power protocol and allocation will remain at 13W (LLDP) until port down/up cycle
2147483607 2019-Jun-18 04:46:34 Warning %LINK-W-Down: gi3
2147483608 2019-Jun-18 04:46:34 Informational %LINK-I-Up: gi7
2147483609 2019-Jun-18 04:46:33 Informational %NT_poe-I-PowerNegStatus: Port gi2 power negotiation moved to expire state, power protocol and allocation will remain at 13W (LLDP) until port down/up cycle


Is it possible the port is not negotiation the correct power output to the cameras?