port disabled

[BigK]

I have this issue and could not figure out why it is happening 

• sho int Gi4/0/16
  GigabitEthernet4/0/16 is down, line protocol is down (err-disabled)

• interface GigabitEthernet4/0/16
  switchport access vlan 20
  switchport mode access
  switchport voice vlan 50
  device-tracking
  authentication host-mode multi-domain
  authentication open
  authentication order dot1x mab
  authentication priority dot1x mab
  authentication port-control auto
  mab
  trust device cisco-phone
  dot1x pae authenticator
  dot1x timeout tx-period 10
  storm-control broadcast level 0.10
  storm-control multicast level 0.10
  auto qos voip cisco-phone
  spanning-tree portfast
  spanning-tree bpduguard enable
  service-policy input AutoQos-4.0-CiscoPhone-Input-Policy
  service-policy output AutoQos-4.0-Output-Policy

switch log

• Feb 26 12:25:33.129: %PM-4-ERR_DISABLE: security-violation error detected on Gi4/0/16, putting Gi4/0/16 in err-disable state
• Feb 26 12:25:33.133: %AUTHMGR-5-SECURITY_VIOLATION: Security violation on the interface GigabitEthernet4/0/16, new MAC address (9890.96c2.2eed) is seen.AuditSessionID Unassigned
• Feb 26 12:25:34.130: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet4/0/16, changed state to down

[ognyan.totev]

Hi,please shut the port than on the port type no switchport port-security and no shut the port.

[Mohammed al Baqari]

Hi,

Can you try the command 'authentication mac-move permit'?

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[socratesp1980]

I had the same issue where I was doing dot1x for an endpoint where was behind an IP phone. My workaround is to add:

authentication violation replace