ZyXEL Communications XGS-4526 - Manual (Page 427)

Appendix A IP Addresses and Subnetting
XGS-4526 User’s Guide
427
The following table is a summary for subnet planning on a network with a 16-bit
network number.
Configuring IP Addresses
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 Switch.
Once you have decided on the network number, pick an IP address for your Switch
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
Switch will compute the subnet mask automatically based on the IP address that
Table 165 16-bit Network Number Subnet Planning
NO. “BORROWED”
HOST BITS
SUBNET MASK NO. SUBNETS
NO. HOSTS PER
SUBNET
1 255.255.128.0 (/17) 2 32766
2 255.255.192.0 (/18) 4 16382
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