Port flapping/down issue on Cisco SG550XG switch

[Cyber25]

Hello friends,

I have ran in one strange issue.

I have a SG550XG-24T 24-Port 10GBase-T Stackable Managed Switch into our network. It is a single switch. There are various ESXi hosts connected to the interfaces of this switch. One of the port has went down and link state is down too.

Port te1/0/10 enabled
State: disabled Role: disabled
Port id: 128.10 Port cost: 2000000
Type: N/A (configured:Auto ) Internal Port Fast: No (configured:Auto)
Designated bridge Priority : 32768 Address: a0:f8:49:f2:30:0e
Designated port id: 128.10 Designated path cost: 0
Guard root: Disabled BPDU guard: Disabled
Number of transitions to forwarding state: 0
BPDU: sent 29800826, received 0

sh interfaces status te 1/0/10
Flow Link Back Mdix
Port Type Duplex Speed Neg ctrl State Pressure Mode
-------- ------------ ------ ----- -------- ---- ----------- -------- -------
te1/0/10 10G-Copper -- -- -- -- Down -- --

I checked the cables and ports and everything is fine. I am not able to understand why is the port down. Please help me.

[pieterh]

does your ESXi host have multiple connections to the SG ?
ESX itself does not participate in spanning-tree, but will forward the packet from the SG from one port to the other
so the switch will shut down one of the ports

[Cyber25]

Yes the ESXi have two connection but to different switches. One is connected to other SG550 which is switch-007 and one connection is to this SG550 which is switch-008.

[balaji.bandi]

Check using other ports, and if you any other device with 10GB interface connect to this port and check.

[Cyber25]

One of the port(port 12) was down so I swapped the cables and both ports came up. However I restored them to original state and port 12 is up since then but port 10 is again down. 

Edit:

I think it is problem with port maybe as when I swapped the cables with other port today and saw on the switch, port te1/0/10 is flapping and when I run cable diagnostics test the switch thinks that port te1/0/10 is down. And even if it comes up for few seconds, it will have the speed of 100M while the port is set on auto mode on both sides and the other side is 10G.

[balaji.bandi]

ok is the all in same place, go via any patch panels ?

[Cyber25]

All in same rack.

[balaji.bandi]

when you get chance reload the switch and test it - or connect any other device and test as suggested to see if the port is ok to confirm.