ive never used a virtual router before...
only used vlans and vswitches... is there anything special about vrouters? like how vswitches have tagging and trunking?...
I'm saying you should literally run a router firmware in a VM so I guess it would depend on which firmware you used.
if you want to go really crazy with options linux can also be used as a router in fact it's what a lot of the firmwares are based on