You might want to re-read the post above yours carefully. Specifically:Vlans were designed to separate networks so you need routing from and to a different vlan/network. As far as this printer it does not know anything about vlans's it will just get the default network and gateway. On the computer side you can make a static route with proper gateway to be able reach the correct network also it needs to have a link (virtual ethernet) to both networks.
Last but not least why does this printer needs to be in a different network????
If he can ping it, the routing is fine.But even if I give the IP address to the HP configurator, it can't see the printer, even if I can ping it.
Lion is garbage because of the stupid scrollbars, not having Rosetta, and now preventing a simple hack.