What I need is fairly simple... I am working on a HA project. And I have several "nodes" sending heartbeats to a master node. The master node has a redundant back-up, and these two master will each have their own IP address and then share one. Therefore, if the master node goes down, the back-up will take over and take over the shared IP address. This will be useful so I won't have to do any reconfiguration on where the heartbeats are sent. But, there could be a loss of heartbeats received, and the system could *think* these are failing when in reality they are not able to send their heartbeats because the have the old MAC address in their ARP cache. So, gratuitous ARP was told to me as the solution for this. And, with explanations on the list as well as re-reading Stevens chapter on it I think this is a viable solution. If it is NOT a system call or system API in the Linux Kernel, would it not be easier just to issue a remote command to flush the ARP caches? i.e. 'rsh -d <hostname>' so that node would be forced to re-issue the initial ARP? TIA -Brad ----- Original Message ----- From: "Nivedita Singhvi" <nivedita@sequent.com> To: "Brad Bonkoski" <bbonkoski@xyterra.com> Cc: "lnml" <linux-net@vger.kernel.org> Sent: Monday, August 13, 2001 1:09 PM Subject: Re: ARP > > 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 > > > > Some operating systems provide support in the kernel (i.e. the > kernel issues a gratuitous arp when appropriate). Linux doesnt, > but I heard that there was a user level utility available that > forced a gratuitous arp. I'd be interested in a pointer to it > myself, if someone can supply one. > > If there isnt one already, I'd be happy to implement one, if > there's interest(?). > > thanks, > Nivedita - : 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
