How to get an inventory of all DNS entries for a given domain?

I agree w/ David re: most servers not being configured to allow zone transfers. Having said that, you can try giving a zone transfer a shot.

dig @nameserver example.com axfr

Substitute in your nameserver's name and your domain name.

On Windows, you can use nslookup in interactive mode to do a zone transfer. From the nslookup prompt:

server nameserver
ls -d example.com

Again, substitute in your nameserver's name and your domain name.

Try all the nameservers-- sometimes I find that one of them will allow zone transfers.

Generally not.

If the DNS servers are configured to allow zone transfers to anywhere then you can read the whole zone file that way - but it is very unusual for servers to honour such requests unless they are from the providers other name servers or admin/monitoring machines.

You can list DNS servers using any DNS client nslookup, host, dig ... with dig run

dig domain.tld ns

If the DNS server allow the tranfert zone that is used generally for DNS database replication and backup, you can get the zone file using the dig utility like this:

dig @dns.server domain.tld axfr