One of the most tedious tasks in the initial lab setup (at least for me) is the IP address configuration, which usually includes a number of typos and mixups on the WAN links. You can simplify then WAN address configuration if you configure only one end of the WAN link and let PPP do the rest. For example, you could use the following configuration to configure WAN link on your core router …
hostname Core-2… and use IPCP negotiation on the POP router to pick up the WAN IP address:
description link to POP
ip address 10.0.2.1 255.255.255.252
peer default ip address 10.0.2.2
description link to Core-1
ip address negotiated
You should not configure no peer neighbor-route on the router that gets dynamic IP address, as the subnet mask is not assigned with IPCP; you need the IPCP-generated host routes if you want to do hop-by-hop telnet between the routers.