352 Appendix ■ Answers
41. D. Ping uses ICMP, the Internet Control Message Protocol, to determine whether a system
responds and how many hops there are between the originating system and the remote
system. Lauren simply needs to filter out ICMP to not see her pings.- D. 8 02.1x provides port-based authentication and can be used with technologies like
EAP, the Extensible Authentication Protocol. 802.11a is a wireless standard, 802.3 is the
standard for Ethernet, and 802.15.1 was the original Bluetooth IEEE standard. - D. 1 000BaseT is capable of a 100-meter run according to its specifications. For longer
distances, a fiber-optic cable is typically used in modern networks. - C. PRI, or Primary Rate Interface, can use between 2 and 23 64 Kbps channels, with a
maximum potential bandwidth of 1.544 Mbps. Actual speeds will be lower due to the
D channel, which can’t be used for actual data transmission, but PRI beats BRI’s two B
channels paired with a D channel for 144 Kbps of bandwidth. - C. SPIT stands for Spam over Internet Telephony and targets VoIP systems.
- D. Bluesnarfing targets the data or information on Bluetooth-enabled devices. Bluejacking
occurs when attackers send unsolicited messages via Bluetooth. - C. Layer 6, the Presentation layer, transforms data from the Application layer into
formats that other systems can understand by formatting and standardizing the data. That
means that standards like JPEG, ASCII, and MIDI are used at the Presentation layer for
data. TCP, UDP, and TLS are used at the Transport layer; NFS, SQL, and RPC operate at
the Session layer; and HTTP, FTP, and SMTP are Application layer protocols. - D. Fully connected mesh networks provide each system with a direct physical link to every
other system in the mesh. This is very expensive but can provide performance advantages
for specific types of computational work. - C. PPTP, L2F, L2TP, and IPsec are the most common VPN protocols. TLS is also used
for an increasingly large percentage of VPN connections and may appear at some point in
the CISSP exam. PPP is a dial-up protocol, LTP is not a protocol, and SPAP is the Shiva
Password Authentication Protocol sometimes used with PPTP. - C. FDDI, or Fiber Distributed Data Interface, is a token-passing network that uses a
pair of rings with traffic flowing in opposite directions. It can bypass broken segments by
dropping the broken point and using the second, unbroken ring to continue to function.
Token Ring also uses tokens, but it does not use a dual loop. SONET is a protocol
for sending multiple optical streams over fiber, and a ring topology is a design, not a
technology. - C. The Physical layer includes electrical specifications, protocols, and standards that
allow control of throughput, handling line noise, and a variety of other electrical
interface and signaling requirements. The OSI layer doesn’t have a Device layer. The
Transport layer connects the Network and Session layers, and the Data Link layer
packages packets from the network layer for transmission and receipt by devices
operating on the Physical layer.