CISCO Certification Questions

Classless routing protocols advertise subnet mask information along with the network prefixes. Classful routing protocols do not. Therefore, for a classful protocol, all subnets for the major network number being used must be the same length. Also, classful protocol cannot support discontiguous networks prefixes.

OSPF intra-area and interarea routes, and possibly a default route. External routes from ABRs are blocked, and external routes from ASBRs are converted to N1 or N2 routes.

OSPF intra-area and interarea routes, and a default route. External routes are not advertised into a stub area.

The router with the highest interface priority will be the router ID. If all the interface priorities on the multi-access network are the same, the router with the highest router ID will be the DR.

The last four digits are the used at the access layer to identify a particular telephone. The next three numbers are used at the distribution layer to identify an exchange that services several phone numbers. The area code is used at the core level for routing between different regions.