Mark E. Mallett wrote:
That last part is the main reason. It's a legacy thing, not all of which I have control over. I'd rather just make it keep working than try to get everybody to change things.
Well, you could actually rename the "ns1.ispc.org" host to "ns1.dnsist.net", for example, and all .org domain names that use ns1.ispc.org will update. (Note that there is no guarantee that other registries will pick up the change, but you don't actually need them to do so in order to delete the nameserver hosts. Your problem is related only to .org domains using them.)
Not that I would necessarily recommend this, really; renaming nameservers across registries is a bit of black magic. It's probably more understandable to leave things alone and updating the nameserver hosts at the registry if you change their addresses, which should be standard practice anyway.
What you're sort of saying is "I know that in the general case, nameserver hosts need to be updated at the respective registry when their IP address changes, but I happen to know that there is something about these three nameserver hosts which should cause the registry to never announce glue records, and I therefore don't want to bother updating them at the registry when they change". That's dangerous, really: even if the registry didn't hand out undesirable glue records in the case of geezer.org, you'd be in trouble if you ever changed ispc.org to use a ns[0-9].ispc.org nameserver. The registry *would* then have to hand out glue records, and they would be wrong unless you had remembered to fix them.
So even if you don't expect the .org registry to hand out glue records for your nameserver hosts, I think you should still make sure that the IP address on file for that host at the registry is correct. That way everything always works.
-- Robert L Mathews, Tiger Technologies http://www.tigertech.net/
