I don't think it's quite right that the routers send their ARP broadcast replies when you simply do a shut/no shut. From the testing I have doen, they don't even seem to do this if you physically disable and enable the interface by removing and reinserting the cable. They only do this on a reboot.
However, I definitely agree with the gist of Marty's response. I think you are troubleshooting (or preparing to troubleshoot) a non-existant problem. The problem will fix itself when your 6513 boots and sends its ARP broadcast replies. Changing the MAC address to match the address that was on your router seems like overkill and also rather dangerous. Are you sure you're not going to ever put that router in the same broadcast domain again?? By the way, we had a power failure yesterday where I work part-time and had to do something similar to what you are doing (move the IP address and functionality from one mission-critical device to a different device that was still working). There were no glitches whatsoever. All operating systems adopted to the new IP/MAC match immediately. (We don't have Solaris though, just Cisco, Mac OS, and Windows). Good luck! Keep us posted on what happens! :-} Priscilla John Neiberger wrote: > > I just tried this and it appears that the behavior is a little > different > on routed virtual interfaces on the 6513. I'm running 12.1(11) > IOS and > with debug arp turned on I didn't see the duplicate IP test or > the > gratuitous ARP. > > Or, I'm just blind and I don't see it but I've run the test > several > times just to make sure. > > Thanks, > John > > >>> Marty Adkins 8/19/02 8:06:55 PM > >>> > John Neiberger wrote: > > > > 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. > > > With the new box being a Cisco, the good answer is you won't > have to > do anything. For many many years, Cisco routers have performed > several > operations anytime you "no shut" an interface or change its IP > address: > 1) ARP broadcast as a duplicate IP address test (and hope nobody > replies). > 2) Gratuitous ARP reply sent to the broadcast MAC. > The latter causes every local host to blindly overwrite its > previous > ARP entry. Life goes on undisturbed... > If you want to observe this behavior without a protocol > analyzer, type > "debug arp", then perform the change. > > Marty Adkins Email: > [EMAIL PROTECTED] > Chesapeake NetCraftsmen, LLC o:410.757.3050, > p:[EMAIL PROTECTED] > 1290 Bay Dale Drive, Suite 312 http://www.netcraftsmen.NET > Arnold, MD 21012-2325 Cisco CCIE #1289 > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=51763&t=51674 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
