ZyXEL Communications 128MH user manual Subnet Mask Notation continued, Examples of IP Subnet Masks

Prestige 128MH PSTN Router/Hub

Table 3-1.	Subnet Mask Notation (continued)
Number of Bits		Dot Decimal Value
	3	224
	4	240
	5	248
	6	252
	7	254
	8	255

Table 3-2 lists some examples of IP subnet masks and the number of hosts that are allowed. Consult your network administrator or MIS specialist if you are unsure of this value.

Table 3-2.	Examples of IP Subnet Masks
IP Subnet Mask		Number of Host IDs	Number of Bits
255.255.255.0		254	24
255.255.255.128		126	25
255.255.255.192		62	26
255.255.255.224		30	27
255.255.255.255		1	32

An IP address consists of two parts, the network ID and the host ID. The IP Subnet Mask is used to specify the network ID portion of the address, expressed in dotted decimal notation.The Prestige will automatically calculate this mask based on the IP address that you assign. Unless you have special need for subnetting, use the default mask as calculated by the Prestige.

Chapter 3 Internet Access Application 3-3