Check Point NG: Next Generation Security Administration
Learn to implement a strong security solution using Check Point VPN-1/FireWall-1.
TABLE OF CONTENTS Check Point NG: Next Generation Security Administration
Appendix A: Class C Subnet Mask Cheat Sheet
Overview
This cheat sheet can come in handy when working with network addresses and subnet masks. A standard netmask is written 255.255.255.0 which is equivalent to the aggregate /24. Using aggregates has become popular because computer people tend to be lazy and it only requires three keystrokes.
| Netmasks and Aggregates | |||
|---|---|---|---|
| Subnet Mask | 255.255.255.0 | Hex Mask | 0xffffff00 |
| Subnet Bits/Aggregate | 24 | Host Bits | 8 |
| Number of Subnets | 1 | Hosts per Subnet | 254 |
| Network Address | Host IP Range | Broadcast Addresses | |
| .0 | .1 - .254 | .255 | |
| Subnet Mask | 255.255.255.128 | Hex Mask | 0xffffff80 |
| Subnet Bits/Aggregate | 25 | Host Bits | 7 |
| Number of Subnets | 2 | Hosts per Subnet | 126 |
| Network Address | Host IP Range | Broadcast Addresses | |
| .0 | .1 - .126 | .127 | |
| .128 | .129 - .254 | .255 | |
| Subnet Mask | 255.255.255.192 | Hex Mask | 0xffffffc0 |
| Subnet Bits/Aggregate | 26 | Host Bits | 6 |
| Number of Subnets | 4 | Hosts per Subnet | 62 |
| Network Address | Host IP Range | Broadcast Addresses | |
| .0 | .1 - .62 | .63 | |
| .64 | .65 - .126 | .127 | |
| .128 | .129 - .190 | .191 | |
| .192 | .193 - .254 | .255 | |
| Subnet Mask | 255.255.255.224 | Hex Mask | 0xffffffe0 |
| Subnet Bits/Aggregate | 27 | Host Bits | 5 |
| Number of Subnets | 8 | Hosts per Subnet | 30 |
| Network Address | Host IP Range | Broadcast Addresses | |
| .0 | .1 - .30 | .31 | |
| .32 | .33 - .62 | .63 | |
| .64 | .65 - .94 | .95 | |
| .96 | .97 - .126 | .127 | |
| Network Address | Host IP Range | Broadcast Addresses | |
| .128 | .129 - .158 | .159 | |
| .160 | .161 - .190 | .191 | |
| .192 | .193 - .222 | .223 | |
| .224 | .225 - .254 | .255 | |
| Subnet Mask |
Copyright Syngress Publishing, Inc. 2002 under license agreement with Books24x7
