Basic Tcp/Ip Concepts - Anybus Communicator PROFINET IRT User Manual

Network Configuration
4.2

Basic TCP/IP Concepts

IP Address
The IP address is used to identify each node on a TCP/IP network. IP addresses are written as
four decimal integers (0–255) separated by dots, where each integer represents the binary val-
ue of one byte of the IP address. This is known as dot-decimal notation.
Example: 10000000 00001010 00000010 00011110 is written as 128.10.2.30
The following IP addresses are reserved for special purposes and cannot be used:
0.n.n.n
127.n.n.n
n.n.n.0
n.n.n.255
Subnet Mask
The IP address is divided into three parts: Net ID, Subnet ID and Host ID. A subnet mask is a
32-bit binary pattern, where a set bit allocates a bit for Network/Subnet ID, and a cleared bit al-
locates a bit for the Host ID. The subnet mask is usually written in dot-decimal notation.
Example: To make the IP address 128.10.2.30 belong to subnet 128.10.2, the subnet
mask must be 255.255.255.0.
Subnet mask:
Default Gateway
For devices to be able to communicate over Ethernet they must either belong to the same sub-
net or communicate via a gateway or router.
A gateway or router routes communication between networks, i.e. it enables the nodes on one
network to access the nodes on another. The default gateway address in the TCP/IP settings of
your product specifies the IP address of the gateway or router on the local network.
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Anybus Communicator ™ PROFINET
First byte zero — used for broadcast messages
First byte 127 — used for loopback addresses to the local host
Last byte zero — identifies a whole network/subnet
Last byte 255 — used for broadcast messages
11111111 11111111 11111111 00000000 (255.255.255.0)
Net ID / Subnet ID
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IRT (2.32) User Manual
Host ID
SCM-1202-033-EN 1.1
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