What IP addresses should I put to x,y,z,A (explained below)?

[silvercats]

http://oi46.tinypic.com/29usx81.jpg . In this image there is a network diagram

All rooms (shown by 1,2,3.....,11) should be in different networks.
X,Y,Z are the router's ports. What IP addresses should I put them?(Is it a must to put an IP to xyz parts?)
A is the router. what IP should I give it too?
Also I am hoping to give different IP addresses to other ports too (which leads to 1,2,3,.....11 rooms). That is not a much problem.but above ones are.

[donami]

for the labs use 172.16.0.0/26 i.e this gives you 62 host in each subnet,172.16.0.1 to 172.16.0.62,172.16.0.65 to 172.16.0.126,172.16.0.129 to 172.16.0.190,172.16.0.193 to 172.16.0.254,172.16.1.1 to 172.16.1.62,172.16.1.65 to 172.16.1.126,172.16.1.129 to 172.16.1.190 and so on, an dyou can use a class c private address space for the other departments possibly 192.168.0.0/26 which allows you to have 62 host in each of th subnets

[JorgeM]

It looks like based on the diagram that the expectation is that you further subnet the 192.168.1.x and 192.168.2.x subnets. Create subnets based on the number of hosts in each location, allowing for some room to grow.

The only other thing you have to consider is that a router was placed in the IT department box. That means that you have to create a segement between A and Z, then assign a subnet to the IT department box.

I have a subnet calculator that I built..you are free to use it to figure out the subnets and number of hosts... http://www.itgeared.com/tools/ip-subnet-calculator/

With regard to your question about what IP on the router's ports... the IP you will use will be the "default gateway" for each segement. To maintain consistnency, pick either the first available IP in each subnet or the last available IP in each subnet.

I hope this gets you going. I am hesitant to give you more information as this is a learning experience that you should definately grasp if network administration is what you are working on.