I have my RVS-4000 configured using static IP addresses in the LAN configuration. The users use DHCP to get their addresses (for the most part, a couple may have static IPs set on the computer). I have the maximum number of DHCP users set to 1 to restrict the ability of people to log in to the system. That one address is locked down.
The internal address of the router is set to 18.104.22.168. It doesn't conflict with anything on my network. I have 35 static IPs. About half of them are uing IP Based ACL to limit their access time but that doesn't seem to bear any relationship to what drops off.
Almost daily one or more of the users will lose their IP address and a hard reset of the router is required. The user this happens to seems random and it may be more than one but seldom all of them. The network includes Windows7 (Home & Pro), a FreeNAS, Macs (Leopard and Snow Leopard), iPad, iPods, an iPhone and an AirPort Extreme used as a WAP (DHCP is disabled). The AirPort is plugged directly into the router and has a staic ip on the RVS-4000 but is set to DHCP. It seems to be the most common problem child.