Understand how to configure the subnet issued by the provider?

Question

Computer networks

It costs Dir-100 - a cable from the provider is plugged into it. it has an external IP address 178.49.27.** We
asked the provider for a second IP - it issued
Adress 178.49.137.?0
Mask 255.255.255.252
HostMin: 178.49.137.?1
HostMax: 178.49.137.?2
Broadcast: 178.49.137 .?3
Actually - how to use this thing?
In Dir-100 it is possible to disable NAT
The task is to have two external IPs - one to the IP phone to part, the other to the local network in the office.
What equipment is needed, how to connect it, configure it - how can all this be done? Setting up networks is simple and other settings of the router don’t cause problems for me, but here I’m directly faced with the fact that I don’t understand how to do it and I can’t find on the Internet where exactly what I need was written.
Thanks in advance.

Answer 1

nat must be turned off, and it is necessary to transfer it to the router mode.
In general, it's easier to put a switch, plug in a provider cable and two devices on which you need to get these 2 devices and configure them.

Answer 2

Your task does not quite fit the existing equipment.
You need both nat (for the office) and direct routing (for the phone).
At best, you could implement this on dir-320 with firmware for asus from enthusiasts, by finishing the configuration to the state when From the web interface, there is already little to manage. Or put open wrt on your existing piece of iron, if it certainly allows. Judging by Google, it won’t allow, but this needs to be clarified additionally.
An alternative option is to set up NAT on one machine, while it alone will be plugged into your router with a separate patch cord (namely in router mode), and public address number 1 will hang on this interface, and the phone will also be plugged into the router, and will have a public address number 2. All the rest go through the machine with NAT (however, another dir-100 can act as its role)

Answer 3

It will work in router mode
Transfer the link to router1, write down the main address on the WAN (which is on it now), on the internal one - write down the gateway address from the network given to you (now you have 192.168.1.1 registered there), for example 178.49.137.1
Plug another router (router2) into the router in NAT mode, and the phone
On router2, enter the WAN address 178.49.137.2
on the phone - 178.49.137.3