ARP Address Resolution Protocol

12-04+ARP+Address+Resolution+Protocol.pdf

#IP to MAC Address Resolution

The sender needs to know the receivers IP and MAC address to form the packet that's going to send

We can point the sender directly to the destination IP address or a user friendly FQDN such as www.cisco.com

DNS maintains a mapping of FQDNS to IP's

ARP is used to map the IP address to a MAC Address.

Host ARP Commands

ARP Replies are saved in a hosts ARP cache so it doesn't need to send an ARP request everytime it wants to communicate

WINDOWS:

View ARP Cache: arp -a Clear ARP cache: netsh interface ip delete arpcache

Linux:

view Arp cache: arp -n Clear Arp Cache: ip -s -s neigh flush all