Class C VLSM Assistant
When
working with Class C addresses, you have a maximum of 254 host
addresses that you can use. When you need to share the host addresses
across multiple subnets, the task of assigning addresses becomes more
complex. Using a routing protocol (ie RIP, IGRP) that does not
support variable length subnet masks (VLSM) wastes valuable host
addresses. VLSM maximises the number of host addresses that can be
used . To use the results from this Assistant, you must use a routing
protocol that supports VLSM (ie OSPF, EIGRP, RIP V2, etc).
The new Class C VLSM Assistant will calculate variable length subnet masks and host address ranges for up to 30 subnets each with a differnet number of hosts.
The Assistant will initially prompt you for your Class C network address. Next it will ask you for the number of subnets you want the assistant to calculate masks and address ranges for. Finally, you are required to enter the number of hosts in each subnet. The Assistant will then calculate the address ranges and Variable length subnet mask for each subnet. If a given subnet cannot be accomodated in this calculation, it will be flaggd accordingly.
The Assistant gives preference to subnets with larger numbers of hosts. These subnets will be assigned address ranges before subnets with a smaller number of hosts. An example of the output from the report is displayed below: