logging un-authorized zone transfers

[Lance Spitzner]

How do I log all un-successful (un-authorized)
zone transfers?

This is the logging I currently have, which
only logs successfull transfers.  How do I
log all unsuccessful (un-authorized)
transfers?

--- /etc/named.conf ---

logging {
        channel bind_xfers { // - "Log all zone transfers
	file "/var/adm/bind_xferlog";
	severity info;
	};

	category xfer-in { bind_xfers; };
	category xfer-out { bind_xfers; };

--- snip snip ---

Thanks!

Lance Spitzner
http://www.enteract.com/~lspitz
Internetworking & Security Engineer
Dimension Enterprises Inc