With an upgrade to Shoreware version 9.0 or 9.1 the installer soon realizes that Shoretel has decided to add the LLDP feature to the phones and has turned this option on by default after the installation.  Since most switches are already set up with the LLDP option turn on, this causes the phones to display a “MAC/PHY Config Mismatch” error and constantly reboot.  To resolve this problem, you are forced to manually configure the phones and set the LLDP feature to OFF or disable this feature from the management console on the switches.  Below are the steps for each method of resolving this problem:

Manually Configure LLDP Off On Phones
1. Reboot the phone, enter the password when prompted and hit #.
2. Clear all values? Choose No.
3. Hit # through the options until you are prompted for LLDP? Toggle this option to Off (press * to toggle) and hit #.
4. At this point it should prompt you to Save All Values? Choose Yes and the phone should automatically boot up error free.
*This procedure needs to be done on every single phone connected.

Turning Off LLDP On Managed Switch (most common manufacturers)
Dell Switch
1. Remote onto Management Interface using IP Address.
2. Go to System, then to LLDP-MED, then LLDP Properties.
3. Uncheck the Enable LLDP box, and Apply Changes.
4. Reboot the switch, which will force all the phones connect to reboot as well, but this time they will boot normally.
*Keep in mind that these procedures have to be configured on all switches that have phones attached.

Cisco Switch Config Commands
lldp run
!
!
!
interface FastEthernet1/0/1
switchport voice vlan 2
spanning-tree portfast
sh lldp

Global LLDP Information:
Status: ACTIVE
LLDP advertisements are sent every 30 seconds
LLDP hold time advertised is 120 seconds
LLDP interface reinitialisation delay is 2 seconds

Switch#sh lldp

Global LLDP Information:
Status: ACTIVE

Shoretel Support has informed us that they will releasing a new phone config file with their next update which will set LLDP OFF by default.  Until that release, the above methods will resolve the issue.