Is there different IP for Router, switch, modem, and server? and how can I find each ip for each?

Answer 1

There is definitely a different ip for your server, but not necessarily on the rest. It really depends on your configuration and equipment. If you are in a larger business, the switch and router may have their own unique ip addresses. However, more than likely you have the following:
A modem with a unique "public ip address" You would have to log-in to the device to learn it.
A router that is given a "private ip" or "subnet address" that has been created by itself and is different from the modem.
A switch may or may not have its own ip address.
Your server will get a private ip address assigned from the router.
If you can log-in to your router it should have all the info for all the devices

Answer 2

First there are public and private (non-routeable) IP addresses.

Private IP addresses do not access the internet. Probably the most common private IP address is 192.168.1.1 which is the default for many home grade routers. All have the same IP but there is no confusion because it is internal and stays within the private network.

Public IP addresses are routed across the Internet.

A router has 2 sides, a WAN (Public) side and a LAN (private side).

The router public side is a routeable IP and it can be a static IP or a dynamic IP, depending upon which type you want and pay for from your ISP. If you have a dynamic public IP you configure your WAN side to accept a dynamic IP. Your WAN ip will change periodically. If you have a static IP from your ISP, you configure your WAN for the specific static IP you were provided by the ISP.

The router LAN side has nonrouteable IP addresses it doles out to downstream devices when they log on if you configure it to provide Dynamic Host Configuration Protocal (DHCP). The router itself has a LAN IP that enables LAN devices to access the router. The router and all LAN devices are on the same subnet (e.g. 192.168.1.x where x ranges from 1 - 254 or 192.168.0.x or 192.168.2.x etc; you cannot get a network to work if the router address was 192.168.1.1 and you wanted to dole out via DHCP, LAN IP addresses in the form of 192.168.2.x on a simple router.

It is unwise to allow DHCP to assign all available LAN IP addresses because some devices should have a static IP. Because of this, usually you will reserve a pool of IP addresses in the subnet for static devices.

Network switches that are unmanaged almost never have an IP address. Managed network switches have a LAN IP address - and usually this is not assigned by DHCP but is static.

Servers should also have a static IP. Print servers, network printers, etc also should have static IP.

Note that you can have your server assign DHCP to the network instead of the router if you have a server controlled network.

If the router provides DHCP, the default gateway is the router LAN IP; if the server provides DHCP, the default gateway is the server and the server's default gateway is the router.

To determine the default gateway, open command prompt (start - run, type in cmd and hit enter) and type in "ipconfig" without the quotes and hit enter. If you are connected to the network and you should see the IP address of the pc you are on, the subnet mask, the default gatway.

Your modem is controlled by the ISP. It provides the public IP address to the router. I do not beleive it has its own IP but if it did the ISP would be the one connecting to it from their side.