Networking Basics Questions and Answers

Answer: B

Correct answer: show access-lists

show access-lists displays every access list configured on the router, of all protocols, with each statement and the number of packets it has matched - those counters being invaluable when diagnosing a list that is not behaving as intended. show ip interface reveals where a list is applied but not what is in it, and the interface commands show neither.

Answer: D

Correct answer: A network that has only one entry and exit point.

A stub network reaches the rest of the internetwork through a single point, so there is only one possible path in or out. Because no routing decision is available, it needs no dynamic routing protocol - a default route out of it and a static route into it are sufficient, which is why stubs are used to reduce routing overhead. A network with no exit at all would be isolated rather than a stub.

Answer: C

Correct answer: FCC

The Federal Communications Commission regulates interstate and international communications by radio, television, wire, satellite and cable, and it allocates the radio spectrum within the United States. The ITU-T issues international telecommunication recommendations but does not regulate commerce; the IEEE develops standards such as the 802 series; and ISOC is the parent body of the IETF.

Answer: C

Correct answer: ICMP

Ping sends an ICMP echo request and waits for an echo reply, timing the round trip. It carries no transport layer header at all, which is why a ping can succeed while an application still fails - reachability at the network layer says nothing about whether a TCP port is open. ARP resolves addresses within a segment, and BootP is a predecessor of DHCP.