The Switches to be used are the 3750G-12S-E, a redundant set to take advantage of HSRP. The network model is based off the Honeywell Level 1 and Level 2 network for their Fault Tolerant Ethernet (FTE) design that basically uses broadcasts packets to communicate every nodes status and allows honeywell to boast of a 1 millisecond recovery time within the redundant system - (network design attached) The FTE technology is over 10 years old and was based on the STP protocol as I understand from reading their patents and researching. The control network itself is highly secure and has no direct connections or routes to the internet, thus the reason I question the need for the Enhanced Image. Data being routed to networks above level 2 will be passed to the DMZ for internal plant access and will have to traverse level 4/5 routers to get to the outside world. I see the EMI as more of an internet IP protocol necessity that would not provide much in the way of supporting the basic level 2 routing requirements.
