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Is it possible to use vSwitches on ESX 4 to allow multiple identical private subnets to be natted out to an external subnet?

I'm used to the logic of natting a single private subnet out to a routable subnet on a physical network, but can I configure something to take, say 5 port groups, all in their own vSwitches and all using the same /24 subnet and end up with all appropriate outbound traffic from ALL of these subnets down to a single IP representative of the physical ESX machine they are coming from?

I'd assume that as a NAT is occurring there is a suitable managed state table, meaning that a response packet from a physical remote machine will be put back on the right originating subnet even though that IP might exist on 4 other VM subnets.



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up vote 0 down vote accepted

Not inherently no, vSwitches are just that switches - purely layer 2 devices, obviously NAT is, in general terms, an IP-specific function.

As for your second paragraph, yes you can great multiple port groups on the same vlan and create vNICs in a single VM for each one, within that VM (depending on your OS of course) you could team them together to a single IP but that's more to do with the OS config really.

Feel free to clarify your question if I've misunderstood so far.

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That's not quite what I mean. Sounds obvious in my head... Maybe a simpler version is better... I know I can do NAT networking under ESX, but can I do it effectively with multiple identical internal subnets – Chris Phillips Jan 26 '11 at 20:10
ESX doesn't do NAT though does it? That's just player / server / workstation isn't it? Hmm...... Back to the drawing board I guess. – Chris Phillips Jan 26 '11 at 21:27
No, sorry about that. – Chopper3 Jan 26 '11 at 22:18

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