This seems to work fine:
dhclient eth0 ifconfig eth0:1 192.168.1.105 up
But not this:
ifconfig eth0 192.168.1.105 up dhclient eth0:1
Is there any way to get dhcp on a virtual address?
You can't really do this. Your card only has one MAC address but multiple IP interfaces. They will need to have their addresses statically assigned.
When the DHCP server sends back the DHCPOFFER how does it get delivered to
The problem for the DHCPOFFER is that from a Layer-2 perspective the two "devices" (
You can get around this by using VLANs. VLANs will allow you to take the same physical broadcast domain and treat it like multiple "virtual" broadcast domains (hence the name).