Which of the following protocols utilize TCP?（）

单项选择题Which one of the following protocols uses both UDP and TCP ports for the transport layer operation?（）

A.FTP
B.TFTP
C.SMTP
D.Telnet
E.DNS

多项选择题Which of the following protocols utilize UDP as the layer 4 transport mechanism?（）

A.TACACS
B.Telnet
C.SMTP
D.SNMP
E.HTTP
F.TFTP

多项选择题Which of the protocols below use TCP at the transport layer?（）

A.TFTP
B.SMTP
C.SNMP
D.FTP
E.HTTP
F.HTTPS

单项选择题You have just configured a static default route on router TK1. What is the purpose of a default route?（）

A. It is a route to be used when the routing protocol fails.
B. It is a route configured by an ISP that sends traffic into a corporate network.
C. It is a route used when a packet is destined for a remote network that is not listed in the routing table.
D. It is a route manually configured for a specific remote network for which a routing protocol is not configured.
E. It is used to send traffic to a stub network.

多项选择题Some of the TestKing routers have been configured with default routes. What are some of the advantages of using default routes?（）

A. They establish routes that will never go down.
B. The keep routing tables small.
C. They require a great deal of CPU power.
D. The allow connectivity to remote networks that are not in the routing table.
E. They direct traffic from the Internet into corporate networks.