P-2000W_V2 User’s Guide
Subnetting With Class A and Class B Networks.
For class “A” and class “B” addresses the subnet mask also determines which bits are part of the network number and which are part of the host ID.
A class “B” address has two host ID octets available for subnetting and a class “A” address has three host ID octets (see Table 30 on page 111) available for subnetting.
The following table is a summary for class “B” subnet planning.
Table 43 Class B Subnet Planning
NO. “BORROWED” HOST | SUBNET MASK | NO. SUBNETS | NO. HOSTS PER | |
BITS | SUBNET | |||
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| |||
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|
| |
1 | 255.255.128.0 (/17) | 2 | 32766 | |
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|
| |
2 | 255.255.192.0 (/18) | 4 | 16382 | |
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|
| |
3 | 255.255.224.0 (/19) | 8 | 8190 | |
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|
|
| |
4 | 255.255.240.0 (/20) | 16 | 4094 | |
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|
|
| |
5 | 255.255.248.0 (/21) | 32 | 2046 | |
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|
| |
6 | 255.255.252.0 (/22) | 64 | 1022 | |
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| |
7 | 255.255.254.0 (/23) | 128 | 510 | |
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| |
8 | 255.255.255.0 (/24) | 256 | 254 | |
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| |
9 | 255.255.255.128 (/25) | 512 | 126 | |
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| |
10 | 255.255.255.192 (/26) | 1024 | 62 | |
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| |
11 | 255.255.255.224 (/27) | 2048 | 30 | |
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| |
12 | 255.255.255.240 (/28) | 4096 | 14 | |
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| |
13 | 255.255.255.248 (/29) | 8192 | 6 | |
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| |
14 | 255.255.255.252 (/30) | 16384 | 2 | |
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| |
15 | 255.255.255.254 (/31) | 32768 | 1 | |
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| Appendix B IP Subnetting | 117 |
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