Eliot Lear writes: > your implementation And others, notably BIND 8. We're talking about MOST of the Internet's DNS servers here. (See http://cr.yp.to/surveys/dns1.html; I'm assuming that *.com is representative.) This is not a small issue. > could cause interoperability problems by potentially allowing for > different contents of the same zone with the same serial number. No. The _administrator_ can create problems by violating RFC 1034. (Andrews has admitted that his broken configurations violate RFC 1034.) If the administrator follows RFC 1034's consistency requirements, no problems occur. In fact, if the administrator violates RFC 1034 but still follows the easy semi-synchronization rule, no problems occur. Andrews is finally coming out of the closet and arguing that the RFC 1034 rule should be changed (because, with his software, the rule is hard for administrators to follow). But he can't reasonably argue against the semi-synchronization rule. People normally follow that rule anyway; there's no reason to break it; and it guarantees that problems don't occur. ---D. J. Bernstein, Associate Professor, Department of Mathematics, Statistics, and Computer Science, University of Illinois at Chicago