1.2.1.1 Announce Module

TCP/IP Stack Library Announce Module for Microchip Devices

This library provides the API of the Announce Module that is available on the Microchip family of devices with a convenient C language interface. It is a module that belongs to the TCP/IP Stack. The module implements a proprietary network discovery protocol.

This module will facilitate device discovery on DHCP enabled networks by broadcasting a UDP message on port 30303 whenever the local IP address changes

Abstraction Model

Discovering the Board

The Announce module provides an easy way to determine useful parameters for your TCP/IP node’s interfaces. This module works in conjunction with the TCP/IP Discoverer personal computer utility to display an interface’s MAC and IPv4/IPv6 addresses, IPv6 multicast listeners, NBNS host name, and MAC type. During stack operation several events may cause an Announce packet to be broadcast on a particular interface. These include:

• Reception of an Announce packet request on that interface

• A DHCP event on that interface (i.e., the interface has configured a new IPv4 address using DHCP)

• The addition or removal of an IPv6 Unicast Address from an interface (after Duplicate Address Detection)

• The addition or removal of an IPv6 Multicast Listener from an interface

• A user call to the ANNOUNCE_Notify function specifying the interface on which to send the announce message

Each Announce packet is a UDP packet broadcast from the corresponding interface’s IP address. The payload is a series of fields beginning with an 8-bit field ID, followed by field information, followed by a field terminator (0x0D 0x0A). The current field IDs and information formats are:

• 0x01 – This field ID indicates that not all of the interface’s address information could be transmitted in one packet. There is no field information for this ID.

  • 0x01 0x0A 0x0D

• 0x02 – MAC address (6 bytes).

  • 0x02 0x00 0x04 0xA3 0x12 0x0f 0x94 0x0D 0x0A

• 0x03 – MAC type. The field information for this ID is a variable length string describing the MAC type of this interface – "ENCJ60", "ENCJ600", "97J60", "PIC32INT", "PIC32CINT", etc.

  • 0x03 ‘P’ ‘I’ ‘C’ ‘3’ ‘2’ ‘I’ ‘N’ ‘T’ 0x0D 0x0A

• 0x04 – Host name. The NBNS host name of the interface, with trailing spaces.

  • 0x04 ‘M’ ‘C’ ‘H’ ‘P’ ‘B’ ‘O’ ‘A’ ‘R’ ‘D’ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ ‘ 0x0D 0x0A

• 0x05 – The interface’s IPv4 address (4 bytes, big-endian).

  • 0x05 0x0A 0x00 0x01 0x03 0x0D 0x0A

• 0x06 – One of the interface's IPv6 unicast addresses (16 bytes, big-endian). Note that the interface may have more than one of these. The interface also has a corresponding solicited-node multicast address listener for every unicast address that is given. The interface may have static IP address.

  • 0x06 0xFE 0x80 0x00 0x00 0x00 0x00 0x00 0x00 0x02 0x04 0xA3 0xFF 0xFE 0x12 0x0F 0x94 0x0D 0x0A

  • 0x06 0xFD 0xFE 0xDC 0xDA 0x98 0x76 0x00 0x01 0x02 0x04 0xA3 0xFF 0xAA 0xAA 0xAA 0xAA 0x0D 0x0A

• 0x07 – One of the interface’s IPv6 multicast address listeners (16 bytes, big-endian). The solicited-node multicast address listeners will not be included.

  • 0x07 0xFF 0x02 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x0D 0x0A

• 0x08 – One of the interface's IPv6 default router address (16 bytes, big-endian).

  • 0x08 0xFD 0xFE 0xDC 0xDA 0x98 0x76 0x00 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x0D 0x0A

• 0x09 – One of the interface's IPv6 default gateway address (16 bytes, big-endian).

  • 0x08 0xFD 0xFE 0xDC 0xDA 0x98 0x76 0x00 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x0D 0x0A

Library Interface

This section describes the Application Programming Interface (API) functions of the Announce module. Refer to each section for a detailed description.