Ethernet switch controller chip
I have successfully used the Micrel KSZ8999. It may be a bit overkill, but there are numerous options

Datasheet here

Other sources are Microchip and Vitesse to name but two, although when I last used Vitesse, they were very NDA conscious.

Your switch is layer 2 managed, which is available in the Micrel part. I have not looked farther than this, as it provides a solution.