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eg-253:networkq:charlie

Network Configuration: Results

EG-253Practical Internet Technology II
Name Tom Gander and Yapeng Gao
Student Number 442152 & 465858
Date of Submission 17th January 2008

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:

callisto

Question 3

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

Your answer (one of):

/etc/hostname 

Question 4

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

Answer one of:

ifconfig 

Question 5

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

Feature Value
My host's IP address 192.168.2.2
My network's IP address 127.0.0.1
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) 00:10:5a:39:82:87
The frame-level (layer 1) protocol is used to send network messages to the network from my host? Ethernet

Question 6

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

Answer one of:

254 

Question 7

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

Answer one of:

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 one of:

/etc/networks/interfaces 

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

iface lo inet loopback
auto lo
auto eth0
iface eth0 inet static
address 192.168.2.2
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:

127.0.1.1	callisto
# /etc/hosts -- Hosts file for ICCt private network
#
#IP		FQDN			aliases
#
127.0.0.1	localhost.localdomain	localhost callisto
#
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-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

Question 12

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

Answer:

gw-jupiter.icct.com

Question 13

What is the purpose of the Gateway interface?

Answer:

The purpose of the gateway interface provide a bridge (gateway) to the rest of the internet, using Jupiter.

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

<cli prompt=“$” comment=“#”> icct@callisto:~$ 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>

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:

ip_forward=yes

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:

icct@jupiter:/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
syncookies=no

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:

auto eth0
iface eth0 inet static
address 192.168.1.3
network 192.168.1.0
netmask 255.255.255.0
gateway 192.168.1.1
# route to saturn-net
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

from the setting you can see that icct-net 192.168.1.0 is part of icct.net of the interface eth0

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 <cli prompt=“$” comment=“#”> icct@callisto:~$ 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 0 0 0 eth0

</cli>

Add your explanation here.

Question 21

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

Answer <cli prompt=“$” comment=“#”> icct@callisto:~$ 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 14577 0 0 3 12958 0 0 0 BMRU lo 16436 0 4622 0 0 0 4622 0 0 0 LRU

</cli>

Add your explanation here.

Question 22

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

Answer <cli prompt=“$” comment=“#”> icct@callisto:~$ netstat -ta Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 localhost.localdoma:ipp *:* LISTEN tcp 0 0 callisto.jupiter.:55388 server77-68-39-12.l:www TIME_WAIT tcp 0 0 callisto.jupiter.:55387 server77-68-39-12.l:www TIME_WAIT tcp 0 0 callisto.jupiter.:55389 server77-68-39-12.l:www TIME_WAIT tcp 0 0 callisto.jupiter.:55390 server77-68-39-12.l:www TIME_WAIT tcp 0 0 callisto.jupiter.:44192 jupiter.icct.com:ssh ESTABLISHED </cli>

Add your explanation here.

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 <cli prompt=“$” comment=“#”> user@host:~$ command # paste output here </cli>

Question 24

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

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

Explain the result.

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.

Your signature here:

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.
eg-253/networkq/charlie.txt · Last modified: 2011/01/14 13:00 by 127.0.0.1