We managed to identify the issue behind why some students can get to the CLASS volume on a Mac, and some can't. It seems the users that can't don't have a simple password set. As with many educational institutions, we have a fair amount of Macs around, but very little Mac-depth in the network administration side. As far as we're concerned, Mac-networking is almost like Banyan Vines.
The thing that threw us was that we don't set simple passwords as a rule. It turns out that a command-line option for the load of AFPTCP will set it for us if we so choose. What it does is capture the supplied password, check it against NDS, and if it matches it'll set the simple password to the NDS password. One of our desktop-support servers has it set up this way, but the cluster does not. We need to reload AFP on the cluster to get this working, so it'll be either after hours or during break (next week).
The thing that threw us was that we don't set simple passwords as a rule. It turns out that a command-line option for the load of AFPTCP will set it for us if we so choose. What it does is capture the supplied password, check it against NDS, and if it matches it'll set the simple password to the NDS password. One of our desktop-support servers has it set up this way, but the cluster does not. We need to reload AFP on the cluster to get this working, so it'll be either after hours or during break (next week).