Network Configuration: Results

EG-253	Practical Internet Technology II
Name	Uche Azinge
Student Number	583406
Date of Submission	26th November 2010

Instructions

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.

Host Configuration

Question 1

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

Answer (delete as appropriate):

hostname

Question 2

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

Answer:

Ganymede

Question 3

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

Your answer :

/etc/hostname

Question 4

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

Answer

ifconfig

Question 5

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

Feature	Value
My host's IP address	192.168.2.4
My network's IP address	192.168.2.0
The address used by my host to send an IP packet to all hosts on my network	192.168.2.255
The netmask of my host	255.255.255.0
The hardware address (MAC Address) of my LAN-facing network interface connection (NIC)¹⁾	00:16:76:90:39:b3
The frame-level (layer 1) protocol is used to send network messages to the network from my host?	MTU

Comment: Frame level protocol is Etherenet not MTU!

Question 6

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

Answer

Question 7

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

Answer :

Class C

Network Configuration

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.

Question 8

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

Answer

/etc/network/interfaces

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

uto 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

Question 9

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

Answer: 192.168.2.1

Question 10

What is the hostname of the gateway interface?

Answer: Jupiter

Question 11

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       myhost  localhost.localdomain   localhost
127.0.1.1       uche-desktop

# IP            FQDN                            aliases
#
127.0.0.1       localhost.localdomain           localhost myhost
#
192.168.1.1     solaris.icct.co                 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
192.168.1.2     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

Comment. I think your configuration of Jupiter is incorrect. You have:

192.168.1.3     gw-jupiter.icct.com             gw-planets jupiter-if1
192.168.1.2     jupiter.icct.com                jupiter jupiter-if2

should be:

192.168.1.3     gw-jupiter.icct.com             gw-planets jupiter-if1
192.168.2.1     jupiter.icct.com                jupiter jupiter-if2 # <-- should be 2.1

Question 12

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

Answer:

 jupiter.icct.com	  jupiter   jupiter-if2

Question 13

What is the purpose of the Gateway interface?

Answer: A protocol that allows the secure data transfer to and from a server and a network user by means of a program which resides on the server and handles the transaction.

Nope! Where you confused by Wikipedia definition of C-GI perhaps?

Question 14

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

icct@myhost:~$ 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         192.168.2.1     0.0.0.0         UG    100    0        0 eth0

Question 15

How many interfaces (NICs) must a router have?

Answer one of:

2

Question 16

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

Answer: IP forwarding

Question 17

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

Answer:

echo 1 > /proc/sys/net/ipv4/ip_forward

Question 18

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

ip_forward=yes
spoofprotect=yes

Comment The first line is enough.

Question 19

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:

up	route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.4
down	route del -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.4

Checking Your Network

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.

Question 20

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

Answer icct@ganymede:~$ 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         192.168.2.1     0.0.0.0         UG        0 0          0 eth0

netstat -r displays the kernel routing tables.

Question 21

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

Answer

icct@ganymede:~$ 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      9238      0      0 0          7351      0      0      0 BMRU
lo        16436 0       448      0      0 0           448      0      0      0 LRU

netstat -i displays a table of all network interfaces.

Question 22

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

Answer

icct@ganymede:~$ netstat -ta
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 ganymede.jupiter.:42396 lhr14s02-in-f104.1e:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:53138 server77-68-39-12.l:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:53133 server77-68-39-12.l:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:50956 wy-in-f100.1e100.ne:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:51027 wy-in-f100.1e100.ne:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:51025 wy-in-f100.1e100.ne:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:43962 wy-in-f139.1e100.ne:www ESTABLISHED
tcp        0      0 ganymede.jupiter.:42364 lhr14s02-in-f104.1e:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:44498 lhr14s02-in-f154.1e:www TIME_WAIT  
tcp        0      0 ganymede.jupiter.:45286 173.194.0.19:www        ESTABLISHED

netstat -ta shows all active internet connections and their current state.

Testing the Connectivity of your network

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

Question 23

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

Answer

 icct@ganymede:~$ traceroute europa
 traceroute to europa (192.168.2.3), 30 hops max, 60 byte packets
 1  europa.jupiter.icct.com (192.168.2.3)  3.471 ms  3.472 ms  3.462 ms

Question 24

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

Answer

icct@ganymede:~$ traceroute www.swan.ac.uk
traceroute to www.swan.ac.uk (137.44.1.7), 30 hops max, 60 byte packets
1  192.168.2.1 (192.168.2.1)  0.890 ms  0.877 ms  0.865 ms
2  * * *
3  * * *

Explain the result.

The router ignores the pings

Extension Questions

Question 25

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

Question 26

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

Answer

Question 27

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

Question 27

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

Answer

Signature

I hereby submit this work for marking.

Uchechukwuka Azinge

¹⁾

If your host has two or more network cards, the LAN-facing card will be the NIC assigned to your host's static IP address.

ICCT Wiki

Table of Contents

Network Configuration: Results

Instructions

Host Configuration

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Network Configuration

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Checking Your Network

Question 20

Question 21

Question 22

Testing the Connectivity of your network

Question 23

Question 24

Extension Questions

Question 25

Question 26

Question 27

Question 27

Signature