ALL of them.
ALL states and US possessions share DMV reciprocity with one another.
All
Yes, All state DMV's have an interstate pact of reciprocity with one another.
For both criminal extradition and DMV information-sharing purposes they DO have reciprocity, as do ALL states.
Yes
Do they communicate with each other? Yes, they certainly do. Violations will be available in both locations.
Yes, all states and US territories have reciprocity with one another (i.e.: DMV files - court decisions - child support and alimony - etc - etc).
mich - yes
No they do not. Georgia does not have reciprocity with Florida
No according to a police officer that pulled me over in Indianapolis and looked at my Florida license
Florida does not accept reciprocity with any other state. Too many retirees moving there from the North. New York does not accept reciprocity with Florida, though it does from numerous other states.
Most states have more than one cooperative agreement (interstate compact) with other states. (For instance: Mutual enforcement of child support and family court rulings - DMV reciprocity - Extradition agreements - etc - etc)