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eg-253:networkq:darryl

Network Configuration: Results

EG-253Practical Internet Technology II
Name Darryl Lacey
Student Number 526528
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:

titan

Question 3

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

Your answer (one of):

/etc/hosts

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 192.168.3.4
My network's IP address 192.168.3.0
The address used by my host to send an IP packet to all hosts on my network 192.168.3.255
The netmask of my host 255.255.255.0
The hardware address (MAC Address) of my LAN-facing network interface connection (NIC)1) 00:16:76:90:38:74
The frame-level (layer 1) protocol is used to send network messages to the network from my host? MTU

Comment

No, 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/network/interfaces

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

Copy contents of file and paste it as a listing here.

Include a minumum indent of two spaces per line.
Like this. 
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
  address 192.168.3.4
  network 192.168.3.0
  netmask 255.255.255.0
  gateway 192.168.3.1

Question 9

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

Answer: 192.168.3.1

Question 10

What is the hostname of the gateway interface?

Answer:

saturn.icct.com

Comment Actually, the hostname is saturn. icct.com is the domain name!

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:

Copy contents of file and paste it as a listing here. 
Include a minumum indent of two spaces per line.
Like this. 
# /etc/hosts -- Hosts file for ICCT private network
#
# IP	FQDN	aliases
127.0.0.1	titan	localhost.localdomain	localhost 
127.0.1.1	titan
#
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-jupter.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		europoa
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 a web-server in a later
# lab exercise)
# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
icct@titan:~$ 

Question 12

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

Answer:

 gw-saturn.icct.com	

Comment

This is the name of the interface on the WAN side of the router. saturn or saturn-if2 is the name of the interface on the LAN side which is your network's gateway interface.

Question 13

What is the purpose of the Gateway interface?

Answer: Defines a simple and universal interface between web servers and web applications or frameworks to receive data back and forth.

Comment You all got this wrong! You have defined C-GI which has nothing to do with routing!

Question 14

Which linux command shows the routing table for your host?

route 

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

Answer

icct@titan:~$ route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
saturn-net      *               255.255.255.0   U     0      0        0 eth0
link-local      *               255.255.0.0     U     1000   0        0 eth0
default         saturn.icct.com 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:

Enable 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?

/etc/network/options and change the line ip_forward=no to ip_forward=yes

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

Actually it's the first line! The second line is for scurity.

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 <cli prompt=“$” comment=“#”>

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

</cli>

Add your explanation here.

Netstat can print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. The -r part displays the kernel routing tables.

Question 21

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

Answer

<cli prompt=“$” comment=“#”> icct@titan:~$ 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 31495 0 0 0 13948 0 0 0 BMRU lo 16436 0 241 0 0 0 241 0 0 0 LRU </cli>

Add your explanation here.

The -i part displays a table of all network interfaces, (Or if specified,the specified interface).

Question 22

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

Answer

icct@titan:~$ netstat -ta
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 *:www                   *:*                     LISTEN     
tcp        0      0 titan:ipp               *:*                     LISTEN     
tcp        0      0 titan:mysql             *:*                     LISTEN     
tcp6       0      0 localhost:ipp           [::]:*                  LISTEN  

Add your explanation here.

The -ta part shows all active internet connections (if they are servers or established) 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@titan:~$ traceroute 192.168.3.4
traceroute to 192.168.3.4 (192.168.3.4), 30 hops max, 60 byte packets
 1  titan.saturn.icct.com (192.168.3.4)  0.028 ms  0.007 ms  0.007 ms

Question 24

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

Answer

<cli prompt='$' comment=“#”> icct@titan:~$ traceroute www.swan.ac.uk traceroute to www.swan.ac.uk (137.44.1.7), 30 hops max, 60 byte packets 1 saturn.icct.com (192.168.3.1) 0.833 ms 0.815 ms 0.797 ms 2 * * * 3 * * * 4 * * * 5 * * * 6 * * * 7 * * * 8 * * * 9 * * * 10 * * * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * * </cli>

Explain the result.

traceroute is not forwarding the pings to the other network. which leaves a dead connection.

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:

Darryl Lacey 526528

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/darryl.txt · Last modified: 2011/05/19 10:15 by eechris