Remember dup loop
dup loop Technical Terms
dup loop: /d[y]oop loop/ (also `dupe loop') [FidoNet] n. An incorrectly configured system or network gateway may propagate duplicate messages on one or more {echo}es, with different identification information that renders {dup killer}s ineffective. If such a duplicate message eventually reaches a system through which it has already passed (with the original identification information), all systems passed on the way back to that system are said to be involved in a {dup loop}.