Table of Contents
Network Configuration: Results
| EG-253 | Practical Internet Technology II |
|---|---|
| Name | Agnieszka Pawliszyn |
| Student Number | 453126 |
| Date of Submission | 14th Octember 3330 |
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:13:6F:EA |
| 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/network/interfaces
Please include a listing of the file chosen in answer to Question 8:
auto lo iface lo inet loopback 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 eth1 iface eth1 inet dhcp auto eth2 iface eth2 inet dhcp auto ath0 iface ath0 inet dhcp auto wlan0 iface wlan0 inet dhcp
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.icct.com
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:
# /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.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 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
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:
to forward packets to other networks and receive packets from other networks
Question 14
Which linux command shows the routing table for your host?
Answer:
route -n
Run the command identified in Question 14 and reproduce its output here.
Answer
<cli prompt=“$” comment=“#”> icct@europa:~$ route -n Kernel IP routeing 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 0 0 0 eth0
</cli>
Question 15
How many interfaces (NICs) must a router have?
Answer one of:
2 [or more]
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:
icct@europa:~$ 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 (on jupiter)
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:
# 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 auto eth1 iface eth1 inet static address 192.168.2.1
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 saturn-net saturn.swan-icc 255.255.255.0 UG 0 0 0 eth0 jupiter-net * 255.255.255.0 U 0 0 0 eth1 icct-net * 255.255.255.0 U 0 0 0 eth0 default solaris.swan-ic 0.0.0.0 UG 0 0 0 eth0 </cli>
displays the kernel routing tables
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 6935 0 0 0 5651 0 0 0 BMRU eth1 1500 0 6628 0 0 0 7553 0 0 0 BMRU lo 16436 0 6 0 0 0 6 0 0 0 LRU </cli>
Displays the table of all network interfaces
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 gw-jupiter.swan-:domain *:* LISTEN tcp 0 0 jupiter.swan-icc:domain *:* LISTEN tcp 0 0 localhost.locald:domain *:* LISTEN tcp 0 0 localhost.localdoma:953 *:* LISTEN tcp6 0 0 *:ssh *:* LISTEN tcp6 0 0 ip6-localhost:953 *:* LISTEN tcp6 0 0 gw-jupiter.swan-icc:ssh callisto.swan-icc:60851 ESTABLISHED tcp6 0 0 gw-jupiter.swan-icc:ssh europa.swan-icct.:42805 ESTABLISHED
</cli>
display active internet connections for all tcp sockets
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=“$” comment=“#”> icct@europa:~$ traceroute to titan.saturn.icct.com (192.168.3.4), 30 hops max, 40 byte packets 1 jupiter.icct.com (192.168.2.1) 0.277 ms 0.142 ms 0.134 ms 2 gw-saturn.icct.com (192.168.1.4) 1.442 ms 0.238 ms 1.303 ms 3 titan.saturn.icct.com (192.168.3.4) 1.517 ms 1.426 ms 1.417 ms
</cli>
Question 24
Give the output of traceroute from your host to www.swan.ac.uk
Answer <cli prompt=“$” comment=“#”> icct@europa:~$ traceroute www.swan.ac.uk traceroute to www.swan.ac.uk (137.44.1.7), 30 hops max, 40 byte packets 1 jupiter.icct.com (192.168.2.1) 0.224 ms 0.137 ms 0.135 ms 2 * * * 3 * * * 4 * * * 5 * * * 6 * * *
</cli>
packets from the outside are not accepted, so they can't return.
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
# Server venus is a host on icct-net. It needs to know about
# the rest of the network so that it can return messages to the
# saturn and jupiter subnets.
auto eth0
iface eth0 inet static
address 192.168.1.5
network 192.168.1.0 # member of icct-net
netmask 255.255.255.0
gateway 192.168.1.1 # default gateway is solaris
# 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
# Interface in engineering-net is much simpler
auto eth1
iface eth1 inet static
address 192.168.10.1
netmask 255.255.255.0
I don't see a route to 192.168.10.0?
Question 26
Which other files would you need to modify to correctly set up this new router?
Answer /etc/network/interfaces in jupter, saturn and venus (all routers)
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
need engineering-net entry in /etc/networks and need to list the hosts in gateway in the host file (/etc/hots)
Signature
I hereby submit this work for marking.
Your signature here: A.Pawliszyn