Two NICs have been connected using an ethernet cable. The ethernet adapters have been configured as follows:
IP: 22.214.171.124 Subnet mask: 248.0.0.0
IP: 126.96.36.199 Subnet mask: 248.0.0.0
If a subnet mask of 0.0.0.0, 188.8.131.52, 192.0.0.0, 184.108.40.206 or 240.0.0.0 would like to be configured the following message occurs:
The combination of IP address and subnet mask is invalid. All of the bits in the network address portion of the IP address are set to 0. Please enter a valid combination of IP address and subnet mask.
According to this IP calculator a CIDR of 0 is invalid, while X>=1 is allowed.
Why is CIDR < 5 not allowed? Does this mean the lowest possible CIDR is 5 and thus 248.0.0.0?