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mogmios
Contributor
Contributor

MAC address conflict on mgmt net of two ESXi 4 hosts?

We have two ESXi 4 hosts that are having a MAC address conflict on the management networks. It appears that somehow we got the same MAC address on both machines. We configured both drives on the same physical system and just moved one of the drives to the second system (identical hardware) when it arrived and I'm thinking that is the root of the problem. How do I change the MAC address of the management network on one of the systems?

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a_p_
Leadership
Leadership

Never heart of anything like that before.

However, you could try to change the NIC selection for the management network on the Console if you have multiple NICs in your system.

When you go to "Configure management network", compare the available NIC's MAC addresses with the ones in your other system.

If they are different at that level, you could try temporarily switching the management NIC to the second NIC and then back to the first (desired) NIC.

I'm not 100% sure if this works, but I would give it a try.

André

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admin
Immortal
Immortal

Press Alt-F1 on the console of the second machine, type 'unsupported' (it won't echo), and press return. You should be prompted for your root password. Enter the password and press return. At the shell prompt, enter the command:

esxcfg-advcfg -s 1 /Net/FollowHardwareMac

Reboot, and your management network should pick up a new MAC address.

AntonVZhbankov
Immortal
Immortal

Remove NIC and add it back in ESXi console. It will pick new MAC then.


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mogmios
Contributor
Contributor

What I ended up doing was adding a removing the vnic from the console:

vim-cmd hostsvc/net/vnic_remove vmk0

vim-cmd hostsvc/net/vnic_add --ip-address=192.168.x.x --ip-subnet=255.255.0.0 'Management Network'

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