The TestKing network consists of a small office with twenty-five employees that has one connection to the Internet through the TK1 router. What routing configurations are recommended on the TK1 and ISP routers?

The TestKing network is displayed in the diagram shown below:

A. BGP on both the routers.
B. RIP on both the routers.
C. Default routes on both routers.
D. BGP on the ISP router and a static route on TK1.
E. A default route on TK1 and a static route on the ISP router.
F. None of the above

Answer: E

Explanation:

Since private network use RFC 1918 IP address ranges internally, and because of security
reasons, it is generally not possible to use an interior routing protocol with the ISP. This
eliminates choice B. When connecting to an ISP, usually only BGP or static routes are
supported. In this case, since there is only one connection to the Internet, BGP is not
needed so choices A and D can be eliminated. A static default route would be needed on
router TK1 to route to the Internet. In turn, the ISP only needs a specific static route to
reach the LAN of the TestKing network.

Incorrect Answers:

A, D: BGP is not needed on networks that contain only a single link to the Internet.
B. Interior routing protocols are generally not supported with an ISP.
C. A default route on the ISP router would send all of their customers Internet traffic to
the TestKing network, and not the Internet.