Just going through some test questions before my CCENT exam on Friday and I'm thinking about the following question.
Let's say you have a topology with 6 subnets, 3 on the serial links and 3 on the Lan's. RIP2 has been configured as the routing protocol but with no ip subnet-zero on all routers. Lets say one of the serial links was using a /25, implying the block size is 128. Wouldn't both sides of this subnet (IP addresses) be un-usable because the lower side falls under the subnet zero and the other side is the broadcast subnet?