Table of Contents
Network Configuration: Results
EG-253 | Practical Internet Technology II |
---|---|
Name | Big Kwan Sung |
Student Number | 522991 |
Date of Submission | N/A |
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: europa
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 | 192.168.2.3 |
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) | 00:10:5a:39:82:9a |
The frame-level (layer 2) 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/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 minimum indent of two spaces per line. Like this.
auto eth0 iface eth0 inet static address 192.168.2.3 network 192.168.2.0 netmask 255.255.255.0 gateway 192.168.2.1
auto lo iface lo inet loopback
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:
Solaris
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 callisto localhost.localdomain localhost # /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.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 192.168.2.1 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 mimas.saturn.icct.com mimas 192.168.3.3 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 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
Question 12
What is the symbolic name of your network's gateway interface?
Answer:
Jupiter
Question 13
What is the purpose of the Gateway interface?
Answer:
To configure the gateway router so that the sub nets Jupiter and Saturn can connect and communicate with each other, and also to the Internet.
Question 14
Which linux command shows the routing table for your host?
Answer:
Run the command identified in Question 14 and reproduce its output here.
Answer
<cli prompt=“$” comment=“#”> icct@europa:~$ route -n # Output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0 0.0.0.0 192.168.2.1 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:
The ip forwarding (ip_forward=yes) feature so it can send packets to another network
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: /etc/network/options
Reproduce the contents of the file defined in Question 17 to make a Ubuntu host into a router?
Answer
# /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=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:
# Interface in icct-net does the routing, # so needs to know about the rest of the network. auto eth0 iface eth0 inet static address 192.168.1.3 netmask 255.255.255.0 gateway 192.168.1.1 # default for jupiter is solaris # 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 # Interface in jupiter-net is much simpler auto eth0 iface eth1 inet static address 192.168.2.1 netmask 255.255.255.0
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=“$” comment=“#”> user@host:~$ netstat -r Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 192.168.2.0 * 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>
This command displays the routing table on the host like the command “route -n”.
Question 21
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 5809 687 0 1 5971 0 0 0 BMRU lo 16436 0 4 0 0 0 4 0 0 0 LRU
</cli>
This command displays the interface statistics of the network.
Question 22
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 callisto:ipp *:* LISTEN tcp6 0 0 localhost:ipp [::]:* LISTEN </cli>
This command displays the active and passive sockets (connections) on the network as well as the sockets that are waiting to be connected.
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=“$” comment=“#”> user@host:~$ traceroute -n 192.168.3.2 # traceroute to 192.168.3.2 (192.168.3.2), 30 hops max, 60 byte packets 1 192.168.2.1 0.295 ms 0.195 ms 0.188 ms 2 * * * 3 192.168.3.2 15.285 ms 15.228 ms 15.189 ms </cli>
Question 24
Give the output of traceroute
from your host to www.swan.ac.uk
Answer <cli prompt=“$” comment=“#”> user@host:~$ traceroute -n 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 0.245 ms 0.186 ms 0.165 ms 2 * * * 3 * * * 4 * * * 5 * * * </cli>
The result shows, that a ping has been sent through Jupiter (result 1: 192.168.2.1), but the rest of the results show that the pings are not echoed as packets cannot be sent beyond Jupiter.
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
# /etc/network/options - for engineering-net network # set ip_forward=yes if you need to set # up a machine with two network interface cards # as a router ip_forward=yes spoofprotect=yes syncookies=no
# Interface in engineering-net does the routing, # so needs to know about the rest of the network. auto eth0 iface eth0 inet static address 192.168.10.0/24 netmask 255.255.255.0 gateway 192.168.10.1/32 # Engineering server for the new network # 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 # Interface in jupiter-net is much simpler auto eth0 iface eth1 inet static address 192.168.2.1 netmask 255.255.255.0 # route to icct-net auto eth0 iface eth0 inet static address 192.168.1.3 netmask 255.255.255.0 gateway 192.168.1.1
Question 26
Which other files would you need to modify to correctly set up this new router?
Answer
auto eth0 iface eth0 inet static address 192.168.10.0/24 network 192.168.10.0/24 # member of icct-net netmask 255.255.255.0 gateway 192.168.10.1/32 # default gateway is solaris # Route to solaris up route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.1 down route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.1 # Route to jupiter-net up route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.1.3 down route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.1.3 # Route to saturn-net up route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.4 down route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.1.4
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