Zyxel NBG-418N v2 - Инструкция по эксплуатации - Страница 166

Appendix B IP Addresses and Subnetting

NBG-418N v2 User’s Guide

166

C o nfig uring  IP A d d re sse s

Where you obtain your network number depends on your particular situation. If the ISP or your network 
administrator assigns you a block of registered IP addresses, follow their instructions in selecting the IP 
addresses and the subnet mask.

If the ISP did not explicitly give you an IP network number, then most likely you have a single user 
account and the ISP will assign you a dynamic IP address when the connection is established. If this is 
the case, it is recommended that you select a network number from 192.168.0.0 to 192.168.255.0. The 
Internet Assigned Number Authority (IANA) reserved this block of addresses specifically for private use; 
please do not use any other number unless you are told otherwise. You must also enable Network 
Address Translation (NAT) on the NBG-418N v2. 

Once you have decided on the network number, pick an IP address for your NBG-418N v2 that is easy to 
remember (for instance, 192.168.1.1) but make sure that no other device on your network is using that IP 
address.

The subnet mask specifies the network number portion of an IP address. Your NBG-418N v2 will compute 
the subnet mask automatically based on the IP address that you entered. You don't need to change 
the subnet mask computed by the NBG-418N v2 unless you are instructed to do otherwise.

Priva te  IP A d d re sse s

Every machine on the Internet must have a unique address. If your networks are isolated from the 
Internet (running only between two branch offices, for example) you can assign any IP addresses to the 
hosts without problems. However, the Internet Assigned Numbers Authority (IANA) has reserved the 
following three blocks of IP addresses specifically for private networks:

• 10.0.0.0     — 10.255.255.255

• 172.16.0.0   — 172.31.255.255

• 192.168.0.0 — 192.168.255.255

3

255.255.224.0 (/19)

8

8190

4

255.255.240.0 (/20)

16

4094

5

255.255.248.0 (/21)

32

2046

6

255.255.252.0 (/22)

64

1022

7

255.255.254.0 (/23)

128

510

8

255.255.255.0 (/24)

256

254

9

255.255.255.128 (/25)

512

126

10

255.255.255.192 (/26)

1024

62

11

255.255.255.224 (/27)

2048

30

12

255.255.255.240 (/28)

4096

14

13

255.255.255.248 (/29)

8192

6

14

255.255.255.252 (/30)

16384

2

15

255.255.255.254 (/31)

32768

1

Table 76   16-bit Network Number Subnet Planning (continued)

NO . “ BO RRO WED”  

HO ST BITS

SUBNET MA SK

NO . SUBNETS

NO . HO STS PER 

SUBNET