Appendix B IP Addresses and Subnetting
P-660HN-51 User’s Guide
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Subnet Planning
The following table is a summary for subnet planning on a network with a 24-bit network number.
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 Zyxel Device.
Table 113 24-bit Network Number Subnet Planning
NO. “BORROWED”
HOST BITS
SUBNET MASK NO. SUBNETS
NO. HOSTS PER
SUBNET
1 255.255.255.128 (/25) 2 126
2 255.255.255.192 (/26) 4 62
3 255.255.255.224 (/27) 8 30
4 255.255.255.240 (/28) 16 14
5 255.255.255.248 (/29) 32 6
6 255.255.255.252 (/30) 64 2
7 255.255.255.254 (/31) 128 1
Table 114 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