NETGEAR RH348 Private IP Addresses

Reference Guide for the Model RT328 and Model RH348 ISDN Routers

Table 1-2 displays several common netmask values in both the dotted-decimal and the masklength formats.

Table 1-2. Netmask Formats

Dotted-Decimal Masklength

255.0.0.0/8

255.255.0.0/16

255.255.255.0/24

255.255.255.128 /25

255.255.255.192 /26

255.255.255.224 /27

255.255.255.240 /28

255.255.255.248 /29

255.255.255.252 /30

255.255.255.254 /31

255.255.255.254 /32

NETGEAR strongly advises that all hosts on a LAN segment use the same netmask for the following reasons:

•So that hosts recognize local IP broadcast packets

When a device broadcasts to its segment neighbors, it uses a destination address of the local network address with all ones for the host address. In order for this scheme to work, all devices on the segment must agree on which bits comprise the host address.

•So that a local router or bridge will know which addresses are local and which are remote

Private IP Addresses

If your networks are isolated from the Internet (for example, only between your two branch ofﬁces), you can assign any IP addresses to the hosts without problems. However, the 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

NETGEAR recommends that you choose your private network number from this list.

1-12	Introduction