| martek 2003-09-12, 11:17 pm |
| ip subnet-zero is a command that tells the router to use subnet zero. It's one of two subnets that are reserved according to rfc 950 when subnetting.
For instance, if you subnet 192.168.1.0 using a subnet mask of 255.255.255.224, subnet zero is 192.168.1.0 and should (in theory) not be used. The first valid subnet is then 192.168.1.32.
The other reserved subnet is called the broadcast subnet, which in this case would be 192.168.1.224.
Remember the rule of substracting 2 when calculating the number of subnets? Well, subnet zero and the broadcast subnet are those two you substract.
Though nowadays both subnets are commonly used, mainly due to a lack of available IPs.  |