On enwiki, the secure server (i.e. secure.wikimedia.org) is currently written down as using: 66.230.192.0–66.230.239.255
It seems unlikely that the server really uses or needs such a large range.
In addition, we received a report that 66.230.230.230 is operating as a TOR exit node. Since Wikipedia policy is to prohibit anon editing and account creation from TOR nodes, it would be nice to clarify this.
Thanks.
-Robert Rohde