Qn on network and broadcast addressing in subnets

For a Class C IP range 192.168.0.0 to 192.168.0.255.We are having 254 valid hosts .. with 192.168.0.0 being the network IP and 192.168.0.255 being the broad cast IP

Now if we are trying to divide the network to 8 subnets the subnet mask will be 255.255.255.224.Now after subnetting

192.168.0.0 will be the network address for the first subnet or for the whole network ..?

Also if we want a broadcast a message to all the subnets what will the broadcast IP address?

Hi,

Can some one please answer to my question ..

If you have 8 subnets, that means you have used 3 extra network bits leaving you with 5 host bits. The 5 host bits give you a total of 32 hosts per subnet (2^5).
That means you have 8 subnets each with their own network ID having 32 hosts each. Therefore,

192.168.0.0 is the network ID for the first subnet. The others are as follows:

SUBNET ID. USABLE-ADDRESSES BROADCAST-ADD

1. 192.168.0.0 192.168.0.1-192.168.0.30 192.168.0.31
2. 192.168.0.32 192.168.0.33-192.168.0.62 192.168.0.63
3. 192.168.0.64 192.168.0.65-192.168.0.94 192.168.0.95
4. 192.168.0.96 192.168.0.97-192.168.0.126 192.168.0.127
5. 192.168.0.128 192.168.0.129-192.168.0.158 192.168.0.159
6. 192.168.0.160 192.168.0.161-192.168.0.190 192.168.0.191
7. 192.168.0.192 192.168.0.193-192.168.0.222 192.168.0.223
8. 192.168.0.224 192.168.0.225-192.168.0.254 192.168.0.255


As you can see each subnet will have its own broadcast address. Each subnet here is a network on its own and thats why a Layer 3 device is needed for communication between subnets.

There cannot be broadcast to all subnets. The reason being that: For subnets to communicate a Layer 3 device is needed, e.g a Router or Layer 3 switch. These devices don't forward broadcasts from one network to another, hence one subnet to another.

I hope this helps you.

Thx for the clarification !!!!