If the hosts are running snmp, and you have write access, it might be worth seeing if you can get away with a wellfleet trick, wherein you delete individual arp cache entries as they appear in the ipNetToMedia table (or proprietary equivalent) by setting the ipNetToMediaType value to 2, and then adding in the desired substitute entry.
Then again, if you're willing to endure enough downtime to contact each member of the network, you can generate the contents of a batch file/shell script based on ping or your favorite ip troubleshooting utility fairly quickly using a spreadsheet (this, of course, would refer to one written with "modern" programming values in mind, where efficiency and good form are sacrificed in the name of quickly turning out an end product). Or, you can contact all members of a manageably-sized broadcast domain in a matter of seconds by making use of freeware port scanners and other script kiddie toolkit favorites. ----- Original Message ----- From: "John Neiberger" To: Sent: 19 August 2002 5:13 pm Subject: How to force a gratuitous ARP [7:51674] > I'm planning on moving routing responsibilities from a router to our > 6513 and I *really* need to minimize downtime. I'll be moving an > interface IP address from one device to another and this is the default > gateway for all devices on that network. The problem is that all > devices on that subnet will have the wrong MAC address in their ARP > caches. I know that if I issue a unicast ping from the new router it > will force the end host to update its ARP cache but a broadcast ping > does not accomplish the same thing, probably because most devices ignore > a broadcast ping, and I don't feel like pinging every device > individually. > > I can't configure HSRP just to gain the benefit of gratuitous ARP; > simply configuring it will be disruptive and that's what I'm trying to > avoid. > > Any ideas? > > Thanks, > John Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=51687&t=51674 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
