Hello Murray,
If all you want to filter is IP traffic or just L4 traffic based on the content on the IP or TCP/UDP headers you should be good with a router.
For more information about Core and Security Networking follow my website at http://laguiadelnetworking.com
Any question contact me at jcarvaja@laguiadelnetworking.com
Cheers,
Julio Carvajal Segura
Julio Carvajal
Senior Network Security and Core Specialist
CCIE #42930, 2xCCNP, JNCIP-SEC