Hi, difference is in flex stack , 2960s has Flex Stack technology and 2960X and 2960XR have flex stack - plus technology . You can stack these switches together by 2960s-stack module for 2960x and 2960x-stack module for 2960X . But real difference ...
Hi , i can't see router-id for your routers , in ospf protocol , first you need to define a router id . Also your network address is wrong . It suppose to be 172.16.1.252 and 172.16.2.252 with wild mask 0.0.0.3