I'm going to make a pitch for the IP-address based method. Specifically, if you have a set of well known IP addresses for common services, thus something like: 223.255.255.1 - Primary DNS 223.255.255.2 - Secondary DNS 223.255.255.3 - SMTP Mail 223.255.255.4 - Time Server You could very easily support this in ANY network. No additional HW/software required. Specifically: config> ip route 223.255.255.1 255.255.255.255 dns.ser.ver.addr config> ip route 223.255.255.3 255.255.255.255 smtp.ser.ver.addr and so on. You then add an alias on the loopback interface for the "well known" address and make sure your dns/smtp daemon binds to it. Easy to implement, easy to explain, no additional coding changes required, although it would be nice to have stuff ship with these pre-configured. All that you need is a chunk of address space reserved for this and a list of services, each assigned to an address. I think that, barring the need to find/get the IP address block, it should take only a day or so to build an appropriate list of services. The main DNS detractor that I see is figuring out how to hand out DNS server numbers in a CONSISTENT, RELIABLE fashion for roaming users. Remember, that the purpose of this is for someone to be able to find the "correct" server to provide the services which a roaming user will find at different locations depending on where they are dialing in, thus, a config for a user would be: DNS Servers - varies by location SMTP server - varies by location pop3/imap server - always home isp time server - varies by location etc.... Thus the table would only list those services which should vary based on where the user is dialing in/connecting. - Forrest W. Christian (forrestc@imach.com) KD7EHZ ---------------------------------------------------------------------- iMach, Ltd., P.O. Box 5749, Helena, MT 59604 http://www.imach.com Solutions for your high-tech problems. (406)-442-6648 ----------------------------------------------------------------------