Interactive end-of-chapter exercises


Supplement to Computer Networking: A Top Down Approach 8th Edition


"Tell me and I forget. Show me and I remember. Involve me and I understand." Chinese proverb

Textbook Cover

Learning Switches - Advanced

Consider the LAN below consisting of 10 computers connected by two self-learning Ethernet switches. (You may want to re-read section 6.4.3 in the text). At t=0 the switch table entries for both switches are empty. At t = 1, 2, 3, 4, 5, 6, 7, 8, and 9, a source sends to a destination as shown below, and the destination replies immediately (well before the next time step).



Question List


1. At t=6, what two nodes communicated? Write your answer in alphabetical order as x,y (If there is only enough information for 1 node, write that, and if there's no information, write 'n/a')

2. At t=8, what two nodes communicated? Write your answer in alphabetical order as x,y (If there is only enough information for 1 node, write that, and if there's no information, write 'n/a')

3. At t=3, what two nodes communicated? Write your answer in alphabetical order as x,y (If there is only enough information for 1 node, write that, and if there's no information, write 'n/a')

4. At t=9, what two nodes communicated? Write your answer in alphabetical order as x,y (If there is only enough information for 1 node, write that, and if there's no information, write 'n/a')




Solution


1. The transmission at t=6 was L-->H, so the answer is H,L.

2. The transmission at t=8 was A-->K, so the answer is A,K.

3. The transmission at t=3 was G-->K, so the answer is G.

4. The transmission at t=9 was F-->J, so the answer is F,J.



That's incorrect

That's correct

The answer was: H,L

Question 1 of 4

The answer was: A,K

Question 2 of 4

The answer was: G

Question 3 of 4

The answer was: F,J

Question 4 of 4

Try Another Problem

We gratefully acknowledge the programming and problem design work of John Broderick (UMass '21), which has really helped to substantially improve this site.

Copyright © 2010-2021 J.F. Kurose, K.W. Ross
Comments welcome and appreciated: kurose@cs.umass.edu