MDK-ARM Keil, MDK-ARM Datasheet - Page 68

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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Chapter 4. RL-TCPnet Introduction
Dynamic Host Control Protocol DHCP
The DHCP supports automatic allocation of IP addresses and configuration of the
subnet mask within a LAN. A DHCP server must be present within the LAN.
This can run on any station and listens on port 67. When a new station is added
to the network, it will request its network configuration from the DHCP server
before it becomes an active station within the network. The DHCP request
process consists of four stages: discovery, offer, request, and acknowledgement.
An Ethernet station can be assigned automatically an IP
address by a DHCP server. This process consists of four
stages, discovery, offer, request, and acknowledge.
To discover the DHCP server, the new station sends a
UDP broadcast packet with address 255.255.255.255.
When the DHCP receives the DHCP discovery packet, it
will reply back to the new station using the Ethernet
MAC address contained within the discovery broadcast.
In this packet, the DHCP server offers the new station an
IP address. To accept this IP address the new station
replies back with a second broadcast packet. The DHCP
server will send a final acknowledgment packet that
contains the remaining network configuration
information and the lease duration of the IP address.
Internet Control Message Protocol
The Internet Control Message Protocol (ICMP) is mainly used to report errors
such as an unreachable destination or an unavailable service within a TCP/IP
network. ICMP is the protocol used by the PING function that is used to check if
a node exists on a network. The Internet Control Message Protocol must be
implemented in a TCP/IP stack. However, in most embedded stacks only the
PING Echo reply is implemented.