Week 10 Flashcards
When encountering an IPv4-only router, an IPv6 datagram is dropped (T/F)
False
When encountering an IPv4-only router, an IPv6 datagram is _____ an IPv4 datagram, with the _______ as its destination
encapsulated in, next in line IPv6 router
::ffff:ffff:fffff is a valid prefered format IPv6 address (T/F)
False
The method by which a MAC protocol coordinates access to a broadcast medium to prevent and/or reduce collisions is most commonly called:
multiple access
A network with a ____ topology must terminate the endpointe, but with a ______ topology they are connected so there is no endpoint
bus, ring
Which are functions of the Ethernet preamble?
Start signal, Circuit wake-up, Clock synchronization
A multiple access scheme which listens to the channel to make sure it is empty prior to transmitting is called:
Carrier sense protocol
A multiple access scheme which uses a master node to poll each slave node and control who has permision to transmit at any given time is called:
“Taking Turns” protocol
On the sending or receiving host, most of the protocol tasks “below” the application layer of the protocol stack (data encapsulation, IP addressing, etc.) are handled by
the network interface controller (NIC)
MAC addresses are redundant because of IP addresses
False
Most modern Ethernet LANs use a ____ topology
star
For a 10 Mbps link, 100 bit times is 0.1ms (T/F)
False
If an Ethernet sender senses a clear channel, and begins transmission, but shortly thereafter detects a collision, it will…
Terminate transmission and enter an exponential backoff
For a 10Mbps link, 1000 bit times is 0.1ms (T/F)
True
When a mobile unit moves from a home or foreign agent to another foreign agent, the new agent must assign….
a new “Care of” address to the mobile unit
Which of the following are major issues that must be handled in wireless networks, check all that apply
Hosts may frequently move from one network to another
Multi path propagation when radio signals bounce off obstacles
Obstacles that block radio signals
Radio waves are more succeptible to interference than signals carried on cable
the “hidden node” problem
In one type of wireless network, hosts communicate directly with other hosts that are within range. This communication model forms a “grid” called a(n)
ad-hoc network
Which of the following are used in a wireless network such as 802.11n?
Reservation system with RTS and CTS
Collision Avoidance
Carrier Sense Multiple Access
Exponential Back-off / retry for collision resolution
When an organization establishes a network security policy, which of the following should be considered?
The cost of installing “secure” systems
The cost of damage control after various types of security breaches
The value of the information that is stored or transmitted by the site
Given an encryption scheme that uses encrypt(m) to encrypt message m and uses decrypt(c) to get back the original message. What must be true?
decrypt(encrypt(m)) = m
When using an RSA algorithm to construct private and public keys for a public key encryption system, choose prime numbers p and q and then calculate n = pq, z=(p-1)(q-1) Then choose e and d to create the public key and the private key. Suppose that p = 5 and 1 = 11. Which of the following values will work for d and e?
e = 7, d = 63
