ARP
[TCP/IP Stack from Microchip Version 4.50 (Modified)]

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Detailed Description

The Address Resolution Protocol, or ARP, is a foundation layer of TCP/IP.

It translates IP addresses to physical MAC addresses, or locates a gateway through which a machine may be located. TCP applications will not need to access ARP directly. The TCPOpen function will handle both ARP and DNS operations transparently. UDP applications however will likely need to use ARP. Responses to incoming ARP requests are processed automatically. Resolution of ARP requests follows a simple state machine, as indicated in the following diagram.

Files
file	ARP.c
	Address Resolution Protocol (ARP) Client and Server Module for Microchip TCP/IP Stack.
file	ARP.h
	ARP Module Defs for Microchip TCP/IP Stack.
Functions
void	ARPResolve (IP_ADDR *IPAddr)
	Transmits an ARP request to resolve an IP address.
BOOL	ARPIsResolved (IP_ADDR *IPAddr, MAC_ADDR *MACAddr)
	Determines if an ARP request has been resolved yet.
void	ARPFlush (void)
	Flushes the ARP cache.

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Function Documentation

BOOL ARPIsResolved	(	IP_ADDR *	IPAddr,
		MAC_ADDR *	MACAddr
	)

Determines if an ARP request has been resolved yet.

This function checks if an ARP request has been resolved yet, and if so, stores the resolved MAC address in the pointer provided.

Precondition:

ARP packet is ready in the MAC buffer.

Parameters:

	IPAddr	- The IP address to be resolved
	MACAddr	- A buffer to store the corresponding MAC address

Return values:

	TRUE	The IP address has been resolved and MAC address indicates the response.
	FALSE	The IP address is not resolved.

Remarks:

None

void ARPResolve

(

IP_ADDR *

IPAddr

)

Transmits an ARP request to resolve an IP address.

This function transmits and ARP request to determine the hardware address of a given IP address.

Precondition:

ARP packet is ready in the MAC buffer.

Parameters:

IPAddr

- The IP address to be resolved

Returns:

None

Remarks:

None