I know that one can use the "redundancy" option on a static NAT to deal with duplicate IP messages when using the same NAT's on multiple HSRP routers.
I'm trying to think through when this should be necessary. Why do routers with duplicate NAT's, on the same LAN, complain about a conflict if only one NAT is in use? Shouldn't the backup router's NAT be dormant, since there is no traffic going through it?
The best I've found is this, which doesn't really help. The routers advertise the NAT?: