Kaeri,
Sorry it took so long to respond to your post, but I took a break for a bit to get some things done. Anyway, let's take a look at what is going on here.
"The phone boots up, then cycles through:
Waiting for 802.1x authentication
Waiting for LLDP <-- Looking to see if the switch will provide LLDP or CDP for VLAN, L2P, etc..
There's something that flashes here, but it's too fast to catch <-- It is telling you the firmware versions on the phone one being the Main version you see later on.
Waiting for DCHP (Main Ver 05.01.00.16) <-- It is putting out a request for DHCP on the native VLAN
VLAN None PRI None (Main Ver 05.01.00.16) <-- It did not get anything from Waiting for LLDP above
DCHP: Discovery <--It is waiting for an IP Address
TFTP: L2Boot <-- Apparently it got an IP address and it thinks it knows where the phone system and TFTP Server are.
TFTP Server unavailable, continue boot-up <-- It is unable to contact the TFTP Server which by default means it won't be able to contact the phone system since they are normally one and the same.
Contacting Server <-- It will wait here for a minute and then reboot as it cannot contact the Phone System.
The screen flashes - when it works, the phone then resolves into the normal extension screen. <-- My guess is that there is something that is missing as we can try to fix it by manually setting up the phone so it doesn't go through all of that again.
When it doesn't, it repeats the above. It may repeat for 5x minutes, or 3x hours... then, at some point, it works. <-- I think the next step is to manually setup the phone instead of letting the network handle it and see if that fixes the problem. If that does fix the problem then most likely there is something wrong with the DHCP settings the phone is getting, rogue server possibly, or the phone just may be bad.
First step is to find the following information so we can setup the phone manually and see if the problem goes away.
1. The IP Address of the Mitel 5000.
2. An unused IP address on the network.
3. The subnet of the network.
4. The gateway of the network.
Once you have that then reboot the phone and hold down the blue button while it powers up. Press * to accept that you want to configure the phone. Press * to tell it you want to configure the Network Settings. Press # on anything that asks if you want to view the current settings. You will want to press * when you get to IPv4 Settings and then # until you get to Change Static Settings. This is easy to find as there will also be a 0 option to default the phone. Press * at that point and use the up and down arrow keys to go through the settings. Put in the static IP address that you got for item 2 above, the # key is used to put in [.] for the delimiters. Use the arrow keys to get to the next field. Then put in the subnet mask and gateway following the same guidelines. Then you will see something about the TFTP Server and you will put in the IP Address of the 5000, then pass the next field asking for the TFTP port number. Once you get to ICP then put in the IP Address of the phone system again. After that the rest of the fields shouldn't be needed so just arrow through them and press * to Save and then * to Reboot. Hopefully the phone will come up ok and start working, if not then just go through the steps again and use the 0 to default the IPv4 Static Settings and then Save and Reboot again. If you need a more detailed step by step then just ask I will type something up that will go through each option as you get to it and what your responses should be.
Thanks,
TE