Clarifications.

samritz

what i understand is ARP is used to resolve a known ip address to a Mac address.

say you have an nternetwork with two routers connected via a serial link.th routers are connected to LANs. say a pc in a LAN wants to send a packet to another pc on a different network, It sends out an ARP request right? and this ARP request is a broadcast message which routers don't foward by default,so how does the local pc gets the Ip of the remote host in other to frame a packet to be sent out?

dynamik

It gets the router's LAN interface and sends the frame to that. The router then routes that to remote networks.

trackit

samritz wrote: »

what i understand is ARP is used to resolve a known ip address to a Mac address.

say a pc in a LAN wants to send a packet to another pc on a different network, It sends out an ARP request right?

nope... first host (pc in your example) checks if another host is on the same network (logical AND another hosts ip addrss with its own subnet mask), if its on same network it sends ARP request, if it isint (like in your example) it sends packet to its default gateway (router) and router routes the packet forward.

EDIT: of course there is also a proxy ARP but you will learn about it little later