Table of Contents
Network Configuration: Results
| EG-253 | Practical Internet Technology II |
|---|---|
| Name | Richard Parkin |
| Student Number | 637234 |
| Date of Submission | 22nd November 2012 |
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:
Mimas
small m!
— Chris Jobling 2012/12/06 04:28
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 | inet addr:192.168.3.69 |
| My network's IP address | Bcast:192.168.3.255 |
| The address used by my host to send an IP packet to all hosts on my network | inet6 addr: fe80::219:d1ff:fe91:4fc7/64 |
| The netmask of my host | 255.255.255.0 |
| The hardware address (MAC Address) of my LAN-facing network interface connection (NIC)1) | HWaddr 00:19:d1:91:4f:c7 |
| The frame-level (layer 1) protocol is used to send network messages to the network from my host? | ethernet |
You have given the broadcast address for your host's network address and the IPv6 address for the IPv4 broadcast address!
— Chris Jobling 2012/12/06 04:29
Question 6
How many hosts can the sub-net defined by your host's netmask support?
Answer one of:
256
No! The netmask is 255.255.255.0 so 8 bits are available for hosts. 2^8 = 256 possible hosts but you can't use the net address (which would be 192.168.3.0) or the broadcast address (which is 192.168.3.255) so that leaves 254.
— Chris Jobling 2012/12/06 04:31
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:
auto eth0
iface eth0 inet static
address 192.168.3.69
network 192.168.3.0
netmask 255.255.255.0
gateway 192.168.3.1
Copy contents of file and paste it as a listing here. Include a minumum indent of two spaces per line. Like this.
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
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. 127.0.0.1 localhost 127.0.1.1 mimas
# /etc/hosts -- Hosts file for ICCT Private network # # IP FQDN if 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-jupter jupiter-if1 192.168.2.1 jupiter.icct.com jupiter jupiter-if2 192.168.2.22 leda.jupiter.icct.com jumana leda 192.168.2.23 carme.jupiter.icct.com guo carme
# # Saturn cluster # 192.169.3.69 mimas.saturn.icct.com richard mimas 192.168.3.21 hyperion.saturn.icct.com jen hyperion 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 gary dione 192.168.3.3 tethys.saturn.icct.com meg tethys 192.168.3.35 titan.saturn.icct.com ali 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
Question 12
What is the symbolic name of your network's gateway interface?
Answer: saturn.icct.com
Question 13
What is the purpose of the Gateway interface?
Answer:Its is where we can configure how the system is connected to the netowrk
Not really. It defines where packets with IP addresses who's network address does not match the host's network address will be sent for forwarding to the destination network.
— Chris Jobling 2012/12/06 04:35
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=“$” comment=“#”> icct@mimas:/etc$ route Destination Gateway Genmask Flags Metric Ref Use Iface default saturn.icct.com 0.0.0.0 UG 100 0 0 eth0 link-local * 255.255.0.0 U 1000 0 0 eth0 saturn-net * 255.255.255.0 U 0 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=yes
Answer is IP forwarding. Your answer would be part of the later question.
— Chris Jobling 2012/12/06 04:36
Question 17
Which run-time command can be used to make a Ubuntu Linux host act as a router?
Answer:
sudo sh -c “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:
nano /etc/network/options
I expected you to be logged into the host so saturn:/etc/networking/options was the answer I was looking for. Ot at least some indication that you were logged into saturn
— Chris Jobling 2012/12/06 04:39
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:
up route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.4
what about down route?
— Chris Jobling 2012/12/06 04:37
cat /etc/network/interfaces
# This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5).
# This is Jupiter
# The loopback network interface auto lo iface lo inet loopback
# The primary network interface 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
Your gateway router is saturn!
— Chris Jobling 2012/12/06 04:37
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=“$” comment=“#”> icct@mimas:~$ netstat -r Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface default saturn.icct.com 0.0.0.0 UG 0 0 0 eth0 link-local * 255.255.0.0 U 0 0 0 eth0 saturn-net * 255.255.255.0 U 0 0 0 eth0
</cli>
#same “route” command - gives you the kernel routing table information.
Question 21
Give and explain the output of the command netstat -i.
Answer <cli prompt=“$” comment=“#”> icct@mimas:~$ 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 7335 0 0 0 4660 0 0 0 BMRU lo 16436 0 0 0 0 0 0 0 0 0 LRU
</cli>
#displays the statistics for network interfaces currently configured
which statistics specifically?
— Chris Jobling 2012/12/06 04:42
Question 22
Give and explain the output of the command netstat -ta.
Answer <cli prompt=“$” comment=“#”> icct@mimas:~$ netstat -ta #Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:http *:* LISTEN tcp 0 0 localhost:ipp *:* LISTEN tcp 0 0 localhost:mysql *:* LISTEN tcp 0 0 mimas.local:58965 50.97.210.35-stati:http TIME_WAIT tcp 1 0 mimas.local:54753 mulberry.canonical:http CLOSE_WAIT tcp 0 0 mimas.local:58966 50.97.210.35-stati:http TIME_WAIT tcp6 0 0 ip6-localhost:ipp [::]:* LISTEN </cli>
the 't' in this command provides us with the active and passive TCP Unix socket connections, by adding an 'a' sockets that are waiting for a connection are displayed also. The display is of a list of all servers currently on the system.
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=“$” comment=“#”> icct@mimas:~$ traceroute tethys.saturn.icct.com traceroute to tethys.saturn.icct.com (192.168.3.3), 30 hops max, 60 byte packets 1 tethys.saturn.icct.com (192.168.3.3) 0.837 ms 0.836 ms 0.830 ms
</cli>
The question asks you to provide a route to another network. You should have used something on jupiter.icct.com or icct.com. There would then have been at least 2 hops.
— Chris Jobling 2012/12/06 04:44
Question 24
Give the output of traceroute from your host to www.swan.ac.uk
Answer <cli prompt=“$” comment=“#”> icct@mimas:~$ 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) 0.270 ms 0.488 ms 0.478 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>
traceroute uses UDP datagrams to determin the path that packets take over a network. There are 30 lines in a default traceroute response.
Yes, but why is there no response from networks 2-30?
— Chris Jobling 2012/12/06 04:45
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
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