How to connect a block of ip addresses?

Question

System administration

Hello, there is an Internet channel from the provider on the adls line,
the rate says 4/4 and a block of 4 IP addresses.
In the dlink 2640u modem, in the WAN tab, a "static ip" connection is created; one IP
address, mask and gateway are driven in there.
From this modem, the Internet is already going to the server and port forwarding to computers through this external IP address.
Can you please tell me what to use the rest of the IP addresses, it turns out a new static connection needs to be raised in the modem?
Another question, I want to remove the modem later, and raise the connection to the ubuntu server, then how to use the rest of the IP addresses

Answer 1

You also have 1 address.
Of the four addresses - one broadcast, one gateway, one "zero" subnet, one yours (user).
UPD. Do you want to remove the ADSL modem? You cannot do this - this is not a router for wired Internet - this is a modem.

Answer 2

Count yourself.

Answer 3

A block of 4 addresses means the subnet mask is \30.
You cannot use the first and last addresses, because these are the network address and the broadcast address. Realistically, you can only use 2 addresses.
Is it worth bothering with such questions having only 2 addresses?
Work with one address.

Answer 4

the tariff says speed 4/4 and a block of 4 IP addresses.

Right? Maybe one IP, one mask and two DNS? :)

Answer 5

There was a similar situation - they connected optics at work. Blow in my ears - we give 4 white IP addresses.
The tuner came - I ask: "Where are the promised 4 addresses ???"
No, he says no. There is one real and 3 are used for technological purposes.
I had to buy 8 addresses - 3 went for technological purposes, and I had 5 real ones left.
So I join the previous speakers - we need more addresses - buy more than the 4 provided.