ARP - Address Resolution Protocol

Functions
void	ShowArp ()
	Display ARP cache, output will be the stdio serial port.
void	fShowArp (FILE *fp)
	Display ARP cache, output will be sent to the specified file pointer.
BOOL	GetArpMacFromIp (IPADDR4 ip, MACADR &ma)
	Check to see if the specified IP address is in the ARP cache.
void	sendGratuitousArp (int interfaceNumber, IPADDR4 ip)
	Send Gratuitous ARP Request.

Detailed Description

#include< arp.h >

The Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol address (IP Address) to a physical machine address called the Media Access Control (MAC), that is recognized on the local network. An local ARP cache correlating machine IP address to MAC address is maintained on each local machine.

When a host such as a PC computer attempts to communicate with another device, ARP is used to resolve the IP address to the corresponding MAC address.

Function Documentation

fShowArp()

void fShowArp

(

FILE *

fp

)

#include <arp.h>

Display ARP cache, output will be sent to the specified file pointer.

Parameters

*fp	pointer to type FILE.

See also

ShowArp()

GetArpMacFromIp()

BOOL GetArpMacFromIp	(	IPADDR4	ip,
		MACADR &	ma )

#include <arp.h>

Check to see if the specified IP address is in the ARP cache.

This function does not send and arp request, it only checks the arp cache. If you want it to send an arp you could do something like send a ping to the IP address before calling this function.

Parameters

ip	IP address to check for
&ma	MACADR structuire to hold the result (C++ pass by reference)

Return values

TRUE	if found, otherwise FALSE.

sendGratuitousArp()

void sendGratuitousArp	(	int	interfaceNumber,
		IPADDR4	ip )

#include <arp.h>

Send Gratuitous ARP Request.

Used after adding an interface or changing an IP address to update the ARP caches of other hosts on the network. Ensure the interface has a valid IP address before sending.

Parameters

interfaceNumber	Specified which network interface to send on.
ip	The interface's IP address

ShowArp()

void ShowArp

(

)

#include <arp.h>

Display ARP cache, output will be the stdio serial port.

See also

fShowArp()