CSE 265: System and Network Administration

Homework #4

To be sent to cse265 (at) cse.lehigh.edu

1. What are glue records and why are they needed? Use dig to find the glue records that connect our local zone (cse.lehigh.edu) to its parent.

2. Why are the name servers in /etc/resolve.conf specified with IP addresses instead of names?

3. How does a web server recognize which URL to serve when there are multiple web sites (hostnames) associated with the same IP address?

4. What is the MTU of a network link? What happens if the MTU for a given link is set too high? Too low? How can you change the MTU in CentOS?

5. The network 134.122.0.0/16 has been subdivided into /19 networks.


a) How many /19 networks are there? List them. What is their netmask?
b) How many hosts could there be on each network?
c) Determine which network the IP address 134.122.67.124 belongs to.
d) What is the broadcast address for each network?