Gentoo should use a vendor zone as described here: http://www.pool.ntp.org/vendors.html#vendor-zone in the default ntpd configuration. Now the generic pool.ntp.org is used. Of course this applies to openntpd as well. Reproducible: Always Steps to Reproduce: Move /etc/ntp.conf out of the way and re-emenrge ntp.
Gentoo pool now exists http://sources.gentoo.org/net-misc/ntp/files/ntp-client.confd?r1=1.12&r2=1.13 http://sources.gentoo.org/net-misc/ntp/files/ntp.conf?r1=1.17&r2=1.18