Cisco 3750-X 'no shutdown' not working

[pronin_sergey]

Hello,

I'm experiencing strange issue with my WS-C3750X-48T-S.

Model number                    : WS-C3750X-48T-S
System image file is "flash:/c3750e-universalk9-mz.122-55.SE3/c3750e-universalk9-mz.122-55.SE3.bin"

This switch is situated on a remote site and on the 6th of January it was rebooted.

I still do not know the cause, but it might be power outage or smth. We are still checking.

After the reboot I've noticed that one port on this cisco switch is in 'notconnect' state, while I'm pretty sure it should be 'connected'.

I've tried to shutdown the port adminstratevly and do the 'no shutdown' but this port remained in 'disable' state.

#sh run interface Gi1/0/5
Building configuration...
!
interface GigabitEthernet1/0/5
 switchport access vlan 111
 switchport mode access
 shutdown
 no cdp enable
 no cdp tlv server-location 
 no cdp tlv app
 spanning-tree portfast
 spanning-tree bpdufilter enable
 spanning-tree bpduguard enable
end
#conf t
(config)#interface GigabitEthernet1/0/5
(config-if)#no shutdown 
(config-if)#end
#sh run interface GigabitEthernet1/0/5
Building configuration...
!
interface GigabitEthernet1/0/5
 switchport access vlan 111
 switchport mode access
 shutdown
 no cdp enable
 no cdp tlv server-location 
 no cdp tlv app
 spanning-tree portfast
 spanning-tree bpdufilter enable
 spanning-tree bpduguard enable
end

What might cause this problem?

--

Regards,

Sergey

[pronin_sergey]

Looks like I've found smth in the logs:

Jan  7 06:10:58.357: %PLATFORM_ENV-3-LOOPBACK_PORT_POST_ERR: Gi1/0/5 can't be brought up because it failed POST in Loopback test.

Is that port damaged?

[Ivan Shirshin]

Hi Sergey,

Yes, it is HW issue of the faulty port in your case (error is reported by the port ASIC).

There is also a known bug producing the same symptoms but it is already fixed in the release you are currenty running:

    CSCti75491 WS-C3750X-24T-L some ports failed POST in Loopback test .

Kind Regards,
Ivan Shirshin

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