Quoting Craig Sanders (cas@taz.net.au):
is bind running as recursive cache too, or just authoritative server? if both, how much memory does unbound use to do the recursive cache part of what bind's doing?
Good question. I don't know the answer to the second question. BIND9 was performing both authoritative and (light) recursive duties. As suggested by the shell prompt details, the BIND example is the old server in my garage that runs linuxmafia.com. For better or worse, I've been running installations of that old pile of spaghetti code since BIND4 days. Like you, I'm still running BIND9 as a multipurpose nameserver in my own deployment because it's Good Enough[tm]. The NSD instance is running authoritative nameservice for a Linux user group (Silicon Valley Linux User Group) and for a number of sister groups and friends thereof.
also, i need something that acts as both an authoritative and a recursive name-server. from memory, it was difficult or impossible to set that up on the same machine/IP with nsd & unbound.
I have't tried to engineer that, but wouldn't ipaliasing solve that (if indeed you don't prefer segregating functions to different hosts anyway)? FWIW, in a quick check, I also found an example of Unbound running on localhost and NSD binding to the external network interface, which of course means that instance of Unbound is available for recursive service only to local processes. The author runs a second instance on a different host for his local LAN. http://measureofchaos.blogspot.com/2011/04/nsd-and-unbound-install-configure... http://measureofchaos.blogspot.com/2011/04/nsd-and-unbound-install-configure...