The topic of static IP address allocation came up today between a coworker and I, and we had differing ideas on how it should be done. This would be static IP's for our broadband DSL users on non-portable upstream assigned IP space. One method would be to have all our customers run a DHCP client, and those who wanted a static IP would get one reserved in the DHCP server via MAC address. The other method would be to staticaly route their host IP (or a small range) down their pvc and exclude it from the DHCP server range. Some of our arguments: Managing end user MAC addresses for static IP users would be a big hassle. Every time an end user changes a NIC, swaps a server out, buys a new computer, they would need to put a call in because their MAC had changed. Having DHCP assigned statics allows us to change DNS server IP's on the fly with minimal implications. It would also allow us to reassign new IP space without breaking everything (end user mail/dns/etc. would break). Worst case senario is an IP subnet change would occur, the user would DHCP their new "static" IP breaking any server services, but would still be able to connect to the Internet. There were other arguments about possible DHCP spoofing agains't static IP and such.