Virtualbox networking .. Help!

[intel-14309]

Hi.
I am working on Ubuntu 12.04 as host for Virtualbox VMs. In virtualbox I am running two Debian 6 DHCP servers for different networks.

Now, I want those two DHCP server virtual NICs to share one Physical NIC of my host, so that I can connect manageable switch (having VLANs) and connect client machines.

In BRIDGED NETWORKING, for both DHCP SERVERS
When I run my first DHCP server it gives as IP to physical NIC and if connect switch to that NIC, client PCs get IP.
But, when I start my 2nd DHCP server, both servers conflict (as expected) i.e. other DHCP wants to give IP address to the same Physical NIC.

How can I do this? Please Help!

[mizzle]

Your question doesn't really make sense to me.

Anyway, networking options with virtual box are rather elementary. You should consider using KVM, it's a little more configurable.

[Roxoff]

I'm not sure what you're doing is possible. When a new PC connects to your network and does a broadcast for an IP address, all available DHCP servers are going to see that broadcast. You'd need a way to split the traffic to the right DHCP server - there may be a way to filter this traffic using IP tables, but I think that's not a trivial exercise.

Wouldn't this be easier if you ran one DHCP server for both domains? You'd still have the problem with deciding which subnet to put them on, but at least you wouldn't have the conflicts.