Specifications

RSLinx – Training Guide A - 11

Class Decimal Range of First Octet Maximum Networks Maximum Hosts

A 1-126 126 16,777,214

B 128-191 16,384 65,534

C 192-223 2,097,152 254

8) What is a Subnet Mask?

A Subnet Mask is a 32-bit value that allows the TCP/IP protocol stack

to distinguish the Network Address from the Node Address.

9) What are valid Subnet Masks for Standard Class A, Class B, and Class C

networks?

Standard Addressing by definition means that no Subnetting is being

used on the network. This means that the entire Node Address must

be reserved for hosts.

Standard Class A = 255.0.0.0

Standard Class B = 255.255.0.0

Standard Class C = 255.255.255.0

10) Are there any invalid TCP/IP Addresses?

Invalid Addresses Examples

- TCP/IP address of all ones IP Address = 255.255.255.255

- TCP/IP address of all zeros IP Address = 0.0.0.0

- Network Address of all ones IP Address = 255.255.255.100, Subnet Mask =

255.255.255.0

- Network Address of all zeros IP Address = 0.0.0.100, Subnet Mask =

255.255.255.0

- Network Address of 127 IP Address = 127.100.100.100, Subnet Mask =

255.0.0.0

- Node Address of all ones IP Address = 100.255.255.255, Subnet Mask =

255.0.0.0

- Node Address of all zeros IP Address = 100.0.0.0, Subnet Mask = 255.0.0.0

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