AutoIP is used in IPv4 to automatically assign link-local IP addresses on startup to devices on small local networks. Where DHCP requires a DHCP server, AutoIP is a server-less method of choosing an IP address. A link-local address is valid only for communications within the local network segment. It is not necessarily unique beyond the network segment so routers do not forward packets with this type of address as the source or destination address.

In IPv4 the AutoIP module can be used alongside DHCP. If both DHCP and AutoIP are available, the stack uses DHCP first to try to obtain an IP address. If this fails within the configured timeout period, DHCP is disabled and the stack tries to set a link-local address by using AutoIP.

This module is available as an add-on to the HCC MISRA-compliant TCP/IP stack, as shown in the Networking Overview diagram, and is designed specifically for use with it.

FEATURES
  • Conforms to the HCC Advanced Embedded Framework.
  • Compliant with the HCC MISRA-compliant TCP/IP stack.
  • Supports IPv4 addresses within the 169.254.1.1 – 169.254.254.254 range.
  • Designed for integration with both RTOS and non-RTOS based systems.
  • Provides an AutoIP (link-local address) extension for HCC's IPv4 stack.
  • Relates to RFC 3972.