Assume the linksys and cisco servers are both assigned static IP addresses (192.168.0.1 & 192.168.0.249). Furthermore, assume the DHCP server has been granted the largest, contiguous block of available IP addresses in the subnet range to give out as dynamic IP addresses.

Question

Mathematically speaking, how many IP addresses are available in the DHCP pool?

Answer 1

To determine how many IP addresses are available in the DHCP pool, let's first identify the subnet range based on the provided static IP addresses.

1. Static IP Addresses:

   • Linksys server: 192.168.0.1
   • Cisco server: 192.168.0.249

2. Assumptions about subnet:

   • Since both IP addresses begin with 192.168.0, we're likely working with a subnet mask of 255.255.255.0 (/24), which provides a range of IP addresses from 192.168.0.0 to 192.168.0.255.

3. Total IP Addresses in the /24 subnet:

   • There are \(2^8 = 256\) total IP addresses in a /24 subnet, which gives us the range from 192.168.0.0 to 192.168.0.255.

4. Reserved IP Addresses:

   • The IP address 192.168.0.0 is reserved as the network address.
   • The IP address 192.168.0.255 is reserved as the broadcast address.
   • The two static IP addresses (192.168.0.1 and 192.168.0.249) are also reserved for the Linksys and Cisco servers.

5. Calculating available DHCP IP addresses:

   • Total IP addresses in the subnet: 256
   • Reserved IP addresses:
     • 1 (network address) + 1 (broadcast address) + 2 (static IPs) = 4 reserved IPs
   • Therefore, the number of addresses available for dynamic allocation by the DHCP server is:

\[ 256 - 4 = 252 \]

Thus, the number of IP addresses available in the DHCP pool is 252.