That said, how does one issue such a command in Linux? I just looked at the arp man page, and saw no such option for "send gratuitous arp" Are there other man pages I should be looking at? Thanks, Brad ----- Original Message ----- From: "Glynn Clements" <glynn.clements@virgin.net> To: "Brad Bonkoski" <bbonkoski@xyterra.com> Cc: <linux-net@vger.kernel.org> Sent: Monday, August 13, 2001 12:39 PM Subject: Re: ARP > > Brad Bonkoski wrote: > > > I know what ARP is.... > > Gratuitous ARP as defined in TCP/IP ILLUSTRATED VOL.1, The Protocols by W. > > Richard Stevens > > "It occurs when a host sends an ARP request looking for its own IP address. > > This is usually done when the interface is configured at bootstrap time." > > Now, to me, that sounds like RARP, bootp, etc... but I could be wrong. So, > > I ask you all. > > Gratuitous ARP is used *after* the interface is configured, while RARP > is used in order to obtain the IP address with which to configure the > interface. Note that a gratuitous ARP request will have both sender > and target IP address fields filled in (with the same address), while > a RARP request has neither. > > The aforementioned part of Stevens goes on to give the reasons behind > gratuitous ARP, which are basically: > > 1. To determine if any other host is using the IP address; if the > sender receives a reply, it logs an error message. > > 2. In case either the IP address or MAC address has changed. The > gratuitous ARP request should replace any previous entries in other > hosts' ARP caches. > > -- > Glynn Clements <glynn.clements@virgin.net> - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
