How to tackle this question!

Hello,

I am reading tenenbaum's book "computer networks" these days. I am somewhat confused about the two questions of chapter 4 and chapter 5.

Any kind of clarification in this regard will be highly appreciated...By the way, just to let you people know that I have already done my bachelors in CS from Western Michigan University and this is not any kind of acedemic work. I am reading this book and attempting questions just for the sake of my knowledge...thanks for understanding. :)

Qs 1:

A 7 story office building has 15 adjacent offices per floor. Each office contains a wall socket for a terminal in the front wall so the sockets from a rectangular grid in the vertical plane, with a seperation of 4 metres between sockets both vertically and horizontally. Assuming that it is feasible to run a straight cable between any pair of sockets, horizontally, vertically or diagonally, how many metres of cable are needed to connect all sockets using:

a) A star configuration with a single switch in the center


Qs 2: A router has the following CIDR entries in its routing table:

Address/Mask Next hop
135.46.56.0/22 Interface 0
135.46.60.0/22 Interface 1
192.53.40.0/23 Router 1
Default Router 2

For each of the following IP addresses, which interface is used to transmit the packet outbound?

a) 135.46.63.10
b) 135.46.57.14
c) 135.46.52.2
d) 192.53.40.7
e) 192.53.56.7
f) 157.32.8.4

I'll be highly grateful for the help...thanks in advance.

I'm not sure if you're looking for the answers or how to go about solving them yourself.

Unfortunately I can't answer the first question, but I can help you with the second regarding the CIDR blocks.

since i don't know if you want me to give you the answers...I'll give you think link instead to help you figure out which subnet gets routed out of what interface. If a subnet comes into a router and that router doesn't have a route for this network, then it will send it out the default route.

IP Calculator

hope i helped