said by JohnInSJ:that's not even remotely correct - you can use true static mode with static IPs. Your static IP is routed thru the modem. It's a standard config
This is TRUE for STATIC IPs, EVERYBODY, all you need to do is set Disable Firewall for True Static IP Subnet Only / Disable Gateway Smart Packet Detection on the firewall page, and then
use YOUR OWN ROUTER, and Do not use DHCP to get IP address from the SMCD3G, put in the REAL STATIC IP address in YOUR ROUTER, and the SMC will pass all traffic straight thru. (This way your only NAT'd once, as long as you set that up inside YOUR OWN ROUTER. Not that hard to setup traffic rules inside Cisco routers, and almost any security appliance with NAT cabability will work well. We let windows assign DHCP addresses on the LAN side, the Cisco/Security appliance only needs to know what the
address range is. We do not let the Cisco/Security appliance divy out DHCP addresses, even though it can. In a Windows-Server enterprise its better to let it keep track of DNS/DHCP that way it keystones everything and integrates better with Active Directory.
Another thing I do at our office is this :
I connected a cheapy Netgear wireless router directly to one of the 4 ports on the SMCD3G, and I set it up to get a DHCP address from the SMCD3G 10.1.10.X address and I let guests that visit our office use the netgear for internet access, and that keeps them off of the LAN side of our Cisco PIX thus securely on the otherside, just like any other internet user would be. This also makes a nice way to test Cisco VPN Tunnelling software inside our office, thru the Cisco firewall.
There is one more great benifit of setting this type of IPV4 setup, if you ever change providers, then you will only need to make minimal changes IN YOUR OWN ROUTER. all internal IP's would never change, thus no more changing the entire enterprise's IP addresses, as you would keep the NAT'd IPs that you setup in your OWN ROUTER. Change your domain records, update your DNS records, change the static IP in YOUR OWN ROUTER. and the whole change to a new provider would be done quickly.