ZyXEL Communications VMG1312-B Series, Руководство пользователя

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VMG1312-B Series User’s Guide
319
A
P P E N D I X
B
IP Addresses and Subnetting
This appendix int roduces I P addresses and subnet m asks.
I P addresses ident ify individual devices on a net work. Every net working device ( including
com put ers, servers, rout ers, print ers, et c.) needs an I P address t o com m unicat e across t he
net work. These net working devices are also know n as host s.
Subnet m asks det erm ine t he m axim um num ber of possible host s on a net work. You can also use
subnet m asks t o divide one net work int o m ult iple sub- net works.
Introduction to IP Addresses
One part of t he I P address is t he net work num ber, and t he ot her part is t he host I D. I n t he sam e
way t hat houses on a st reet share a com m on st reet nam e, t he host s on a net work share a com m on
net work num ber. Sim ilarly, as each house has it s own house num ber, each host on t he net work has
it s own unique ident ifying num ber - t he host I D. Rout ers use t he net work num ber t o send packet s
t o t he correct net work, while t he host I D det erm ines t o which host on t he net work t he packet s are
delivered.
Structure
An I P address is m ade up of four part s, writ t en in dot t ed decim al not at ion ( for exam ple,
192.168.1.1) . Each of t hese four part s is know n as an oct et . An oct et is an eight- digit binary
num ber ( for exam ple 11000000, which is 192 in decim al not at ion) .
Therefore, each oct et has a possible range of 00000000 t o 11111111 in binary, or 0 t o 255 in
decim al.