Thanks for your reply. Yes, our fallback plan is to use static IP addresses. We are going to have a mix of older units and new units at the same time in the system we are maintaining. I was hoping that the new units would use RARP such that all the units would work equivalently. I have since found that RARP and DHCP are quite different, so I will investigate configuring DHCP.
Using static IP addresses has several drawbacks for us. The units are located in remote areas which makes static programming difficult. If a unit fails and a spare unit has to be dropped in, it's much easier (with RARP) to just slap in the unit and update the /etc/ethers file. With a static address we'd have to make sure the unit is in programming mode and then set the static value
s. Not difficult for us, but the end users will need very exact procedures.
Based on how difficult DHCP is to configure/update/maintain we'll make a decision whether to use that or go with static addresses. Of course then we'll have to decide whether to switch the older devices over to static addresses for consistency, etc. That's progress for you!