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New Member

Novell Clustering

How does a 6k handle a clustering enviroment? Meaning, you have multiple servers in a cluster and server#1 fails and server#2 assumes #1 IP address, how does the switch handle the same IP address on 2 different MAC's on the same switch or VLAN, and if server#2 assumes #1's IP AND MAC address, how does the switch handle the same MAC address appearing on 2 different ports or places in the sam VLAN?


New Member

Re: Novell Clustering

Switches build their forwarding table (CAM table)

based only on MAC address. Routers do the MAC to IP mapping via the ARP table. If a switch sees the same MAC address on another port in the same vlan, it will flush the old entry immediately. However, if the MAC addresses are in different vlans, then it will keep the entry in the CAM table. A switch can learn the same MAC address but it has to be from a different vlan. Also read up on Gratuitous ARP behavior on routers, which is needed to refresh ARP entries in a scenario like what you described.

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