On Fri, Jul 11, 2003 at 07:57:35PM +0300, Shaul Karl wrote: > On Thu, Jul 10, 2003 at 02:39:15PM +0300, Amir Sela wrote: > > > > > > An ARP request? What for? Is it to find the MAC of the default > > > gateway? ARP maps the MACs into IPs, doesn't it? An ARP request would > > > send the MAC address and expects to get in reply the IP that correspond > > > that MAC, isn't it? > > > > > Wrong. it's the other way around. When you ping x.x.x.x, the computer > > knows the IP already. You just typed it, didn't you? What it doesn't > > know is the MAC address of the computer with this IP, so proper > > one-to-one communication can't be established. So, an ARP request is > > sent to request that the computer with the pertaining IP reply its MAC > > address. > > > > > You are right that when I ping x.x.x.x I do know the IP address. > Yet according to the DSL-HOWTO/appendix.html > > ARP > Address Resolution Protocol. Converts MAC addresses to IP > addresses.
Nope. ARP resolves an IP address to a MAC address. You typically know the IP address you want to send a packet to, but not the MAC address. -- Tzafrir Cohen +---------------------------+ http://www.technion.ac.il/~tzafrir/ |vim is a mutt's best friend| mailto:[EMAIL PROTECTED] +---------------------------+ ================================================================= To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
