Yep. IP by definition is required to have a non-zero MAC on the local network (subnet). ARP requires it. Here are some oldies but goodies that discuss this for you (they still apply):
http://support.microsoft.com/kb/168567/EN-US/ http://support.microsoft.com/kb/244331 Basically, the active node has its IP address, and the IP address for the cluster ARPs to the same MAC. When a failover occurs, a gratuitous ARP is broadcast to update the cluster ARP to point to the newly active node (which changes it from the old active node). Regards, Michael B. Smith, MCITP:SA,EMA/MCSE/Exchange MVP My blog: http://TheEssentialExchange.com/blogs/michael I'll be at TEC'2009! http://www.tec2009.com/vegas/index.php From: KevinM [mailto:[email protected]] Sent: Monday, January 05, 2009 3:27 PM To: MS-Exchange Admin Issues Subject: RE: Does I had this same thing happen last week on a 24 hour call and it turned out to be bad NICs I am not willing to believe that 5 NIC's failed on 5 servers at the same site. Last Week. The NIC would fail and cause the cluster to bounce to the other node. The NIC on the other node would fail too and the cluster would fail back. The bouncing would not stop. One of the Symptoms of this was that the NIC had no MAC address in the ARP table on the switch. Replacing the NICs in the servers fixed the bouncing problem and I never trouble shot the MAC issue. Now the customer is reporting that another cluster with the same hardware that went out of warranty in November is showing the same symptom. I don't want to believe that the NICs all went bad, that is what made me ask "Do the Cluster Virtual IP's have a MAC". I would think that they would have too else the broad cast traffic would be horrible. From: Beckett, William (Bill) [mailto:[email protected]] Sent: Monday, January 05, 2009 12:18 PM To: MS-Exchange Admin Issues Subject: RE: Does That would make logical sense but I guess he's looking for what MAC address is used and how is that determined? From: Campbell, Rob [mailto:[email protected]] Sent: Monday, January 05, 2009 3:17 PM To: MS-Exchange Admin Issues Subject: RE: Does It's got to respond to an arp request with something, or it's never going to get any packets sent to it. _____ From: Matt Moore [mailto:[email protected]] Sent: Monday, January 05, 2009 2:14 PM To: MS-Exchange Admin Issues Subject: Re: Does I don't see how it could. Mac address is unique to a piece of HW and assigned by the HW Mfg. at the time of manufacture..... Big Breath... M ----- Original Message ----- From: KevinM <mailto:[email protected]> To: MS-Exchange Admin Issues <mailto:[email protected]> Sent: Monday, January 05, 2009 11:53 AM Subject: Does Does an Exchange Cluster IP have a MAC address? **************************************************************************** ********************** Note: The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. **************************************************************************** ********************** ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
