Ip addresses on routers,servers?

Read up on subnets and ip classes

Read up on subnets and ip classes

The clue is the word Router - routing means passing traffic across subnets, so the gear behind the router will be on a different subnet / ip range to the public IP. The public IPs will be provided by the internet service provider, so unless you have specifically been told what they are, you cannot guess - each is just a 'public IP address'. Generally, an ISP will provide one 'public' IP address for the router itself - regardless of whether it's an ADSL box, cable modem/router or a direct Ethernet connection in. Note: It is possible to get blocks of IP addresses (eg 4 or 8) on a connection. You would then use a switch rather than a router, and each device would have it's own public IP address - and so be directly connectable from anywhere in the world... This is obviously not a good idea for normal desktop computers or printers - only specific servers that actually need 'outside access' to function should ever be connectable from off-site locations. A Router will usually have the facility for 'Network address translation' - NAT. This allows all the machines or devices 'behind' it to have IP addresses in one of the private ranges like 192.168.x.x or 10.x.x.x, with any data addressed outside the local subnet having it's addresses re-written by the NAT router so it appears to come from the public IP of the router. The router also re-writes the reply data frames as they pass through, with the correct private IP of the machine the data is intended for, so each machine functions as if it has a direct internet connection. Because the NAT system only knows which machines to send reply data to (as it knows which sent the request), any unsolicited data from the public internet side is just dumped, the local machines never see it. This makes a NAT router very good protection against hacking and malicious traffic. So, for your machines on each local subnet, pick a block from one of the private IP ranges, eg. Site 1 use 192.168.136.x/24 (/24 = subnet mask 255.255.255.0, 24 ones). Individual machines/ devices then use addresses 192.168.136.1, .2, .3 etc. Site 2 use 192.168.137.x and so on The third section could be anything from 0 to 255, but 0 and 1 are the common defaults on many home routers, so staying away from that is another from of protection for your subnets. If, later on, you need to do something like interconnecting the sites via a VPN, the adjacent internal addressing ranges should simplify the setup. Edit - links added

Generally the client IPs need to be part of the subnet and each subnet consist of a starting and ending IP that are reserved for subnet identification and broadcast purposes. If your router IP is 172.32.0.1 with a subnet mask of 255.255.255.0 then your broadcast address is probably 172.32.0.255 and your subnet ID is 172.32.0.0 anything between those two numbers are valid client IPs. If you change any of the first three octets (172.32.0) it probably won't work. Must be between 172.32.0.2-254. But there are other possible settings you should study it if its part of your curriculum.

Generally the client IPs need to be part of the subnet and each subnet consist of a starting and ending IP that are reserved for subnet identification and broadcast purposes. If your router IP is 172.32.0.1 with a subnet mask of 255.255.255.0 then your broadcast address is probably 172.32.0.255 and your subnet ID is 172.32.0.0 anything between those two numbers are valid client IPs. If you change any of the first three octets (172.32.0) it probably won't work. Must be between 172.32.0.2-254. But there are other possible settings you should study it if its part of your curriculum.