Hello,
VMware's vSwitches are standalone entitites that do not allow for switch stacking. IN order to connect two vSwitches you need to use a lightweight VM that acts as a firewall/router. There are several from which you can choose such as Vyatta, Smoothwall, IPCop, etc.
Or use your RRAS idea.
The device, which ever it is, has 2 vNICs, each connected to one of the vSwitches in use. I.e.
vSwitch A=>Portgroup A=> [vNIC A -- VM -- vNIC B]<=Portgroup B<=vSwitch B
The VM becomes the router between the switches.
Best regards,
Edward L. Haletky
Communities Moderator, VMware vExpert,
Author: VMware vSphere and Virtual Infrastructure Security,VMware ESX and ESXi in the Enterprise 2nd Edition
Podcast: The Virtualization Security Podcast Resources: The Virtualization Bookshelf