DHCP relay for certain MACs

RouterOS General
1

I am in the middle of trying to create some new class C networks. Originally there was one legacy network 192.168.11.0/24 that served three buildings connected by wireless connections. There network grew and the broadcasts became too large so I am trying to separate each building with it’s own Class C network. The problem I have is that they have a legacy VOIP phone system (shoretel) that will eventually be going away but for now it needs to remain operational. It is dependent on a Microsoft DHCP server for it’s booting needs.

I’ve got three mikrotik routers each destined to serve each of the three separate buildings which are connected by wireless links. Each router serves it’s own Class C network.

They had one big class C network that had everything from all three buildings. I am trying to subnet each of these three physical locations yet I have an older phone system that I need to keep active. It relies on a microsoft DHCP server that hosts the legacy network.

Legacy Network for VoiP: 192.168.11.0/24

newrouter-a: 192.168.11.18
— LAN of 192.168.8.0/24
newrouter-b: 192.168.11.19
— LAN of 192.168.9.0/24
newrouter-b: 192.168.11.20
— LAN of 192.168.10.0/24

What I’m wondering is if it is possible for each of my three new Mikrotik routers to handle DHCP for all devices on the LAN except for the VOIP phones. Or is there a DMZ type of thing I could do so that the VoIP phones will get all the BOOTP stuff it needs?

Any advice on the best way to do this is much appreciated. Within the year I plan to switch out the phone system with PIAF or something similar.

2

Hi,

Often phones can process an option from the dhcp service which tells the phone to use a different vlan, and they will jump onto this other vlan. Which could be handled by the microsoft dhcp server, and also can be prioritized appropriately.
You would need to look at the phone(s) manuals.

Many smartish switches can also detect and push the phones onto a separate voice vlan via various means.