This wiki page allows you to record the results of your network configuration exercise. You may need to refer to the configuration handout to complete this document.

Answer all questions based on the host that you are configuring in the lab. Edit this wiki page directly to insert your answers. You will probably find this most convenient to do at the same time as you perform the configuration. Where requested, please include listings of the actual configuration files and command outputs directly in the document. Placeholders have been provided for this purpose. Please follow the formatting hints given in the text.

When the exercise is complete you should sign and submit it in for marking. Deadline for completion is the start of the lab on the last week of this term.

This exercise is worth 20% of the module marks.

Which Linux command gives you information about your computer's name on the network?

Answer (delete as appropriate):

hostname 

Use the command selected in Question 1 to determine your host computer's name? What is the name?

Answer: ganymede

Which configuration file would you need to edit to change your computer's name on the network?

Your answer (one of):

/etc/hosts

Which linux command gives you information on your host's network settings?

Answer one of:

ifconfig 

Use the command selected in Question 4 to complete the following table:

How many hosts can the sub-net defined by your host's netmask support?

Answer one of:

254 

What class of network is the sub-net to which your host has been assigned?

Answer one of:

Class C 

Answer the following questions about your network configuration. Please copy and paste the contents of the files identified in Questions 8 and 11 to your submission.

In which file is the configuration of your Network Interface Controller (NIC) configured?

Answer one of:

/etc/network/options

Please include a listing of the file chosen in answer to Question 8:

# added to fix "can't ping localhost" problem
iface lo inet loopback
auto lo
auto eth0
iface eth0 inet static
address 192.168.2.4
network 192.168.2.0
netmask 255.255.255.0
gateway 192.168.2.1

What is the IP address of the host which serves as the default gateway for your network?

Answer: 192.168.2.1

What is the hostname of the gateway interface?

Answer: jupiter

In which file is the symbolic names of the networks, hosts and interfaces available on the network defined?

Answer one of:

/etc/hosts

Please include a listing of the file chosen in answer to Question 11:

127.0.0.1       localhost
127.0.1.1       ganymede

#  /etc/hosts -- Hosts file for ICCT Private network
#
#  IP           FQDN                            aliases
#
127.0.0.1       localhost.localdomain           localhost myhost
#
192.168.1.1     solaris.icct.com                solaris inet-gateway
192.168.1.2     venus.icct.com                  venus www
#
# Jupiter cluster
#
192.168.1.3     gw-jupiter.icct.com             gw-planets jupiter-if1
192.168.2.1     jupiter.icct.com                jupiter jupiter-if2
192.168.2.2     callisto.jupiter.icct.com       callisto
192.168.2.3     europa.jupiter.icct.com         europa
192.168.2.4     ganymede.jupiter.icct.com       ganymede
#
# Saturn cluster
#
192.168.1.4     gw-saturn.icct.com              gw-saturn saturn-if1
192.168.3.1     saturn.icct.com                 saturn saturn-if2
192.168.3.2     dione.saturn.icct.com           dione
192.168.3.3     tethys.saturn.icct.com          tethys
192.168.3.4     titan.saturn.icct.com           titan
#
# Add other hosts/clusters below here
# (We'll use this to add virtual hosts to the web-server in a later
# lab exercise)

## The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

What is the symbolic name of your network's gateway interface?

Answer: gw-jupiter.icct.com

What is the purpose of the Gateway interface?

Answer: To allow icct-net, jupiter-net and saturn-net subnets to reach each other. The gateway act as a join at each point. Also used to gain access to internet.

Which linux command shows the routing table for your host?

Answer: route Run the command identified in Question 14 and reproduce its output here.

Answer

<cli prompt=“$” comment=“#”> user@host:~$ route # Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface jupiter-net * 255.255.255.0 U 0 0 0 eth0 link-local * 255.255.0.0 U 1000 0 0 eth0 default jupiter.icct.co 0.0.0.0 UG 100 0 0 eth0 </cli>

How many interfaces (NICs) must a router have?

Answer one of:

2 

Which system feature must be turned on if you want a Linux host to act as a router?

Answer: ip forward

Which run-time command can be used to make a Ubuntu Linux host act as a router?

Answer: set ip_forward=yes

In which file is the setting defined in Question 17 set if you want a Ubuntu host to be configured as a router at boot-time?

Answer: /etc/network/options

Reproduce the contents of the file defined in Question 17 to make a Ubuntu host into a router?

Answer

Copy contents of file and paste it as a listing here. 
Include a minumum indent of two spaces per line.
Like this. 
# /etc/network/options - for ICCT network
# set ip_forward=yes if you need to set
# up a machine with two network interface cards
# as a router
ip_forward=no
spoofprotect=yes
syncookies=no

What setting has been added to the network configuration file to define a route to icct-net from your sub-network's cluster-server?

Answer:

Copy contents of file and paste it as a listing here. 
Include a minumum indent of two spaces per line.
Like this. 

The Linux command netstat gives a lot of useful information on your network. In the following 3 questions, reproduce the output of various usages of netstat. You should annotate your results with a brief explanation of what they mean. You may need to print the output and attach to the submission.

Give and explain the output of the command netstat -r.

Answer <cli prompt=“$” comment=“#”>

user@host:~$ netstat -r
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
jupiter-net     *               255.255.255.0   U         0 0          0 eth0
link-local      *               255.255.0.0     U         0 0          0 eth0
default         jupiter.icct.co 0.0.0.0         UG     

</cli>

Add your explanation here. Netstat shows Kernel routing tables as shown above.

Give and explain the output of the command netstat -i.

Answer <cli prompt=“$” comment=“#”> user@host:~$ netstat -i

Kernel Interface table
Iface   MTU Met   RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0       1500 0      2522      0      0 3          2132      0      0      0 BMRU
lo        16436 0      6728      0      0 0          6728      0      0      0 LRU

</cli>

Add your explanation here. Is used to show network interfaces.

Give and explain the output of the command netstat -ta.

Answer <cli prompt=“$” comment=“#”> user@host:~$ netstat -ta

Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 localhost:ipp           *:*                     LISTEN     
tcp        0      0 ganymede.jupiter.:55806 blackboard.swan.ac.:www ESTABLISHED
tcp        0      0 ganymede.jupiter.:55805 blackboard.swan.ac.:www ESTABLISHED

</cli>

Add your explanation here. Show TCP sockets that are waiting for connection.

Install, if necessary, the traceroute command then answer the following two questions.

Give the output of traceroute from your host to any host on one of the other ICCT networks.

Answer <cli prompt=“$” comment=“#”> user@host:~$ command

traceroute to europa (192.168.2.3), 30 hops max, 40 byte packets
1  europa.jupiter.icct.com (192.168.2.3)  2.560 ms  2.566 ms  2.553 ms

</cli>

Give the output of traceroute from your host to www.swan.ac.uk

Answer <cli prompt=“$” comment=“#”> user@host:~$ command

traceroute to www.swan.ac.uk (137.44.1.7), 30 hops max, 40 byte packets
1  jupiter.icct.com (192.168.2.1)  0.210 ms  0.211 ms  0.210 ms

</cli>

Explain the result. shows the time it took to send and recieve packets

A new sub-network engineering-net (192.168.10.0/24) is to be added to the ICCT network. Host engineering (192.168.10.1/32) is a cluster server for this new network. Give the settings needed to set up this host as a router to icct-net, jupiter-net, and saturn-net and a gateway for engineering-net.

Answer

Which other files would you need to modify to correctly set up this new router?

Answer

Summarize the changes that you would you need to make to your host's network configuration to have the new engineering sub-network recognized?

Answer

Which other files would you need to modify to fully configure your host to recognizes the new engineering sub-network?

Answer

I hereby submit this work for marking.

Your signature here: