单项选择题
A. Link state routing protocol is missing.
B. Incorrectly configured IP addresses
C. IGRP is incorrectly configured.
D. Frame relay is not configured.
E. None of the above
多项选择题 After executing the "show host" command, which of the information below would you see?（）
多项选择题 The TCP/IP network model differs from the more popular OSI model. Which of the layers below belong to the TCP/IP model?（）
多项选择题 The Peanut router is able to successfully ping the Serial 0 and Ethernet 0 interface of the Popcorn router, but a ping issued to the Ethernet 1 interface fails. Based on the above output, what are the potential causes of this problem?（）
