1. (1 points) What is the weakness of using passwords as an authentication
mechanism, even when they are encrypted? Describe how you get a more
Weakness of using passwords as an authentication: easy to guess, can be sniffed
11. Write down the contents of your computers ARP cache. What is the meaning of
each column value?
Internet address of the computer
12. What are the hexadecimal values for the source and destination addresses in the
Ethernet frame co
points) Briefly describe (a sentence or two) each of the three major problems in
Decreasing signal strength Decreased signal strength as the distance
between sender and receiver increase.
Interference from other sources same
1. (1 point) What information is used for demultiplexing in TCP? In UDP?
UDP and TCP perform the demultiplexing and multiplexing jobs by
including two special fields in the segment headers: the source port
number field and the dest
1. (1 point) What do the terms client and server mean in the context of a peer-to-peer
protocol? That is, when is a peer called a client and when is a peer called a server?
The process that initiates the communication is labeled as client.
The process tha
(1 point) What are two kinds of multiplexing used in circuit-switched networks?
Frequency-division multiplexing (FDM), Time-division multiplexing (TDM)
(2 points) The following questions refer to the four components of
1. What is the 48-bit Ethernet address of your computer?
2. What is the 48-bit destination address in the Ethernet frame? Is this the
Ethernet address of gaia.cs.umass.edu? (Hint: the answer is no). What device has
this as its Ethernet a
1. Is your browser running HTTP version 1.0 or 1.1? What version of HTTP is
My browser is running HTTP 1.1
Server running HTTP 1.1 too.
2. What languages (if any) does your browser indicate that it can accept t
1. List the different protocols that appear in the protocol column in the unfiltered
packet-listing window in step 7 above.
2. How long did it take from when the HTTP GET message was sent until the HTTP
OK reply was received? (By default,
Wireshark Lab: ICMP
Version: 2.0 2009 J.F. Kurose, K.W. Ross. All Rights Reserved
Computer Networking: A Topth down Approach, 5 edition.
In this lab, well explore several aspects of the ICMP protocol: ICMP messages generating by the Ping program; ICMP mes
Wireshark Lab: DHCP
2009 J.F. Kurose, K.W. Ross. All Rights Reserved
Computer Networking: A Topth
down Approach, 5 edition.
In this lab, well take a quick look at DHCP. DHCP is covered in Section 4.4.2 of the 5th
edition of the textbook. Rec