Dhcp server migration HELP

[sunnytechbequia]

Hi,
I'm trying to upgrade a network at an hotel, where the Mitel 3300 pbx is the DHCP server for the entire property, set as a /22 subnet.
Existing equipment is :
Mitell 3300 mxii (DHCP server) 172.20.224.2
Unifi Dream machine Pro set as a gateway 172.20.227.254
4 x Unfifi 48 poe switches
97 x Unifi Wifi Access Points
93 x Mitel 5312 phones

I would like to install a UXG pro gateway for DHCP server and Vlan creation.
Right now the Mitel technician had it setup as one big 1024 IP network, with Guest and internal network all as one.
Quite a nightmare as you can imagine.

Unfortunately my country only as 1 x Mitel licensed technician, and is unwilling to help me with the change over.
He gave me some "admin credentials", with access to /server-manager, but not full access I'm pretty sure.

I guess I'll have some ports to open on the UXG to allow the 3300 to communicate with the phones, and turn off the DHCP server on it.

If someone wants to offer remote support and assist me, I'm ok with paying for the service.

Ideally network vlan should separate the Mitel, Office network, POS, Guest and Camera.

For now I'd like at least Guest to be separated.

Thanks in advance.

[acejavelin]

Unique VLANs are the way to go... Using LLPD-MED for the voice devices to "push" them into the correct voice VLAN for shared ports.

DHCP is likely handled from server-manager... Best best would be to have the Mitel handle DHCP for the voice terminals, and the Ubiquiti device handle it for all other subnets.

The Mitel doesn't really need ports open or to communicate with the outside world other then for license syncing, no port forwarding should be necessary.

[lundah]

Yeah the existing DHCP settings will be in server-manager under Configuration -> DHCP. If that option doesn't show up, you may be on an older version where the DHCP settings are in the embedded system management (ESM) instead.

Two caveats with DHCP on Ubiquiti: they use Option 125 for their own stuff so you'll have to use option 43 instead, and the string has to be entered as hex with : between each octet. So you'll have to convert your Option 125 string from ASCII to Hex, add a bunch of semicolons, and hope it's right.

[johnp]

Just mentioning that Mitel 125 option has more than the 43 option such that it starts 00 00 04 03 XX or something like that before the ipphone.mitel,com starts. XX is a string length and 00 00 04 03 is an identifier. You can use the tool to create it and get rid of the first 5 values to have the hex for 43

[sunnytechbequia]

Yes the DHCP server option is in server-manager indeed.
I'd really like some assistance to make the transition and disable the DHCP server from the Mitel and use the unifi uxg pro instead.
Any idea who could help me ?
I can pay for the time of course.