CECS 474 COMPUTER NETWORKING INTEROPERABILITY
Netlab 8: WAN Routing and CAN Subnetting in Islanet
Purpose: The purpose of this lab is reinforce the WAN routing information presented during lecture and to
examine the way subnets are calculated and used in Campus Area networks.
Background:
The IslaNet backbone consists of a point-to-point WAN (Wide Area Network) representing the Internet
backbone. It uses OSPF as the routing algorithm to connect five major United States cities: Los Angeles, Las
Vegas, Houston, Chicago, and New York. Islanet also includes a cloud network that resides “somewhere” in the
network-to-network link between Houston and New York. Attached to Los Angeles is a CAN (Campus Area
Network), consisting of the five subnetted departments of Dirtbag-U and routed using RIP.
New York, NY
Chicago, IL
Las Vegas, NV
Los Angeles, CA
Big Apple University
Network Type: LAN
Class C Network
Includes: DNS, HTTP,
DHCP, FTP,VLANs
www.newyork.com
Houston, TX
Dirtbag University
Network Type: CAN
Class B Network
Includes: DNS, HTTP, DHCP,
FTP, RIP Routing
www.losangeles.com
H-Town University
Network Type: LAN
Class C Network
Includes: DNS, HTTP, DHCP,
FTP
www.houston.com
Remote Site (YOOHOO.COM)
Located in the Cloud
Class B Network
Includes: DNS, HTTP, DHCP,
FTP
www.yoohoo.com
Routing:
Recall:
• Routing Algortihms must run at each node to create the forwarding table in the router.
• Routing algorithms run in a distributive fashion.
Two primary routing algorithms are used in the Internet:
1. Link State
 Periodically broadcasts the information about its directly connected links.
 Uses Dijkstra’s Algorithm to find the shortest paths.
 More information is exchanged than in Distance Vector but the nodes have full information about the
network, thus calculation is more robust.
 Used in the OSPF (Open Shortest Path First) protocol.
2. Distance Vector
 Periodically shares path information (the Distance Vector (DV)) only with its neighbors.
 Uses the Bellman-Ford Algorithm to find the shortest paths.
Dr. Tracy Bradley Maples (Fall 2013)
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
 Less information is exchanged than in Link State but the nodes must trust their neighbors’ information,
thus they are vulnerable to network changes.
 Used in RIP (Routing Information Protocol).
Link State Routing on the Islanet WAN (Wide Area Network):
Connect your workstations to Islanet through either New York or Houston.
To connect via New York:




Connect to the Green Port on the wall behind your workstation.
Set your workstation to “Obtain an IP Address Automatically” (DCHP)
You should obtain an IP Address on the network 172.16.16.0/24
Verify this using ipconfig
To connect via Houston:




Connect to the Yellow Port on the wall behind your workstation.
Set your workstation to “Obtain an IP Address Automatically” (DCHP)
You should obtain an IP Address on the network 10.10.10.0/24
Verify this using ipconfig
CHICAGO, IL
LAS VEGAS, NV
(.41)
(.42)
.20.40
40.30
/30
(.4
9)
)
(.9
1.1
.1
9
(.2
(.9)
.48
/30
)
.5
0
(.5
0
/3
.0
/1
28
6
4.8
/
.48
.14
0)
2.
2.
12
0
2.
0 .6
(.50)
30
.8 /
.9 0
.0
9.
20
0)
(.1
.3
0
0)
(.3
5.10.15.28
/30
LOS ANGELES, CA
(.30.3
(.30)
HOUSTON, TX
88.34.69.8/30
9
0.2
(.3
)
(.29)
)
0)
www.yoohoo.com
9.20.90.13
7.5.133.48/30
(.49)
(.30)
Site 3: NEW YORK
[ Big Apple U ]
7.5.133.49 /30 -- WAN
172.16.16.0/24 -- LAN
(.9)
Site 1: LOS ANGELES
[ Dirtbag U ]
88.34.69.9/30 – WAN
192.168.0.0/16 -- CAN
(.50.49)
(.3
0
(.1
0)
0
(.10)
(.50.5
30
)
13
NEW YORK, NY
(.5
0)
67.1.77.28/30
(.29)
Site 2: HOUSTON
[ H-Town U ]
67.1.77.29 / 30 – WAN
10.10.10.0/24 -- LAN
Islanet WAN Design
Dr. Tracy Bradley Maples (Fall 2013)
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
Chicago
( 10
)
( 25
)
New York
Las Vegas
0
)
(5)
(4
( 20
(2
)
0)
( 30 )
Los Angeles
Houston
OSPF link cost for Islanet WAN
In Link State Routing, each node has a table.
Initially, each node knows only about its directly connected links. Let LA = Los Angeles, LV = Las Vegas, HT =
Houston, CH = Chicago, NY = New York. Periodically, all nodes share their directly connected links with all
other nodes by broadcasting.
At the beginning of Dijksta’s Algoritm the table at Node LA looks like this:
Step
Visited Nodes
0
{LA}
1
{
}
2
{
}
3
{
}
4
{
}
5
{
}
LA
LV
HT
CH
NY
Cost, Next
Hop
Cost, Next
Hop
Cost, Next
Hop
Cost, Next
Hop
Cost, Next
Hop
LA,-
LV, 5
HT, 30
∞,-
∞,-
Step by step, add a new path to the set of “Visited Nodes” by selecting the shortest path available (i.e., using
Dijksta’s Algorithm).
Dr. Tracy Bradley Maples (Fall 2013)
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
Exercise A: OSPF Routing on the Islanet WAN
1. Complete the table above using Dijkstra’s Algorithm for the Islanet WAN. Turn-in your solution.
2. Use the tracert command to examine the paths between your workstation and the other routers in the
Islanet WAN. Do the routes calculated by OSPF on the WAN match the routes you calculated using the Link
State (i.e., Dijkstra’s) Algorithm? Show the commands you used to examine the routes on the WAN.
3. What paths would you expect to change if the link between Los Angeles and Las Vegas went down? Ask the
instructor to help you make this physical change in Islanet. What actually happens to the routes? How long
does it take for OSPF to recalculate the routes? Are the new routes what you expected? Show the
commands you used to examine the routes on the WAN.
Calculating Subnet Addresses for the Dirtbag-U CAN (Campus Area Network):
Connect your workstations through Los Angeles.
For Los Angeles:
 Connect to the Red Port on the wall behind your workstation.
 Set up a static address for your workstation.
To calculate your static address for the Dirtbag-U CAN, you must locate an available IP address on the subnet
your workstation connects to.
Netlab 1-3: Connect to University Data Center (IP Address: 192.168.100.2/29)
Netlab 4-6: Connect to College of Engineering (IP Address: 192.168.125.9/29)
Netlab 7-9: Connect to College of Business (IP Address: 192.168.140.20/29)
Netlab 10-12: Connect to College of Mathematics (IP Address: 192.168.130.28/29)
Netlab 13-15: Connect to College of Liberal Arts (IP Address: 192.168.235.37/29)
Hint: Examine the last byte of the network IP Address and use the specified CIDR subnet mask to calculate
the IP addresses available on your subnet.
Exercise B: Subnet Addresses to connect to the Dirtbag-U CAN
1. List your assigned subnet address in CIDR notation: 192 . 168 . ________ . ________ /29
2. List your assigned subnet address in binary:
____________ . ____________ . ____________ . ____________
3. List your assigned subnet mask in binary:
____________ . ____________ . ____________ . ____________
4. List the IP addresses available for use in your subnet in dotted-decimal notation:
5. List the subnet mask that corresponds to your subnet addresses in dotted-decimal notation:
6. How many IP addresses are available for use in your subnet? __________
Dr. Tracy Bradley Maples (Fall 2013)
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
You will need to calculate all of the following information to connect successfully to the network:
IP Address in dotted-decimal: ___________________________
-- From Exercise 4 above
Subnet mask in dotted-decimal: __________________________
-- From Exercise 5 above
Default Gateway in dotted decimal: ______________________ -- Use the IP address of your Dept. switch
Preferred DNS server address for LAN: 192.168.100.250
-- LAN DNS Server
Distance Vector Calculation for Dirtbag-U CAN (Campus Area Network):
Internet
[To Los Angeles WAN]
88 .
3 4.
COLLEGE OF
MATHEMATICS
192.168.130.28/29
6 9.
9
DIRTBAG UNIVERSITY
CAMPUS AREA NETWORK
(CAN)
192.168.0.0/16
(.1)
(.28)
COLLEGE OF
ENGINEERING
192.168.125.9/29
(.2)
)
(.5
)
(.6
)
(.2
(.6)
192.168.30.0/30
19
16
2.
8.
192.168.40.3/30
/3 0
0
.0
/3
.0/2
9
2.
16
19
(.6)
COLLEGE OF
BUSINESS
192.168.140.20/29
(.2
)
8.
23
.3/30
)
(.6
5.
0
30
3/
2.
16
.100
8.
20
(.5
)
5.
19
.168
0 .1
5
8.
Dr. Tracy Bradley Maples (Fall 2013)
68.35
192
.1 0
(.1
)
68
16
COLLEGE OF
LIBERAL ARTS
192.168.235.37/29
2.1
2.
192.1
)
(.1
0
19
)
(.5
(.5)
19
/3
2.1
9.3
.0
25
19
.2
68
UNIVERSITY
DATACENTER
192.168.100.2/29
Dirtbag University
Servers
192.168.100.250
www.losangeles.com
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
RIPng Metric for CAN
subnets
College of Engineering
College of Mathematics
:1
:1
:10
:1
:1
:1
Dirtbag University
Gateway
:1
College of Liberal Arts
:1
:1
University DataCenter
College of Business
Hop metrics used on the CAN
Exercise C: Exploring RIP Routing on the Islanet CAN
1. Use the Distance Vector Calculation Table on pages 7-8 to calculate the paths calculated by RIP on the
Islanet CAN. Submit your completed tables. (Note: you may not need to use all of the tables provided to
reach a steady-state.)
2. Use the tracert command to examine the paths between your workstation and the other Dirtbag-U
departments in the Islanet CAN. Do the routes calculated by RIP on the CAN match the routes you
calculated using the Distance Vector (Bellman-Ford) algorithm? Show the commands you used to examine
the routes on the CAN.
3. What paths would you expect to change if the link between the University Data Center and the College of
Business went down? Ask the instructor to help you make this physical change in Islanet. What happens to
the routes? How long does it take for RIP to recalculate the routes? Are the new routes what you expected?
Verify this using the tracert command. Show the commands you used to examine the routes on the
CAN.
Dr. Tracy Bradley Maples (Fall 2013)
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CECS 474 COMPUTER NETWORKING INTEROPERABILITY
Distance Vector Calculation Table: Here are the initial DVs for the Islanet CAN.
1-Data Center
2-Engineering
3-Mathematics
4-Liberal Arts
5-Business
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
1
--
1
1, 1
1
∞
1
∞
1
1, 1
2
2, 1
2
--
2
2, 1
2
2, 1
2
∞
3
∞
3
3, 1
3
--
3
3, 1
3
3, 1
4
∞
4
4, 1
4
4, 1
4
--
4
4, 1
5
5, 1
5
∞
5
5, 1
5
5, 1
5
--
Each Node shares its DV with its directly connected neigbors. After Node 2 shares its DV:
1-Data Center
2-Engineering
3-Mathematics
4-Liberal Arts
5-Business
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
1
--
1
1, 1
1
2, 2
1
2, 2
1
1, 1
2
2, 1
2
--
2
2, 1
2
2, 1
2
∞
3
2, 2
3
3, 1
3
--
3
3, 1
3
3, 1
4
2, 2
4
4, 1
4
4, 1
4
--
4
4, 1
5
5, 1
5
∞
5
5, 1
5
5, 1
5
--
Continue with each node sharing its DVs with its directly connected neigbors, until all DVs are stable.
1-Data Center
Path
to
Cost,1st
hop
2-Engineering
Path
to
Cost,1st
hop
3-Mathematics
Path
to
Cost,1st
hop
4-Liberal Arts
Path
to
Cost,1st
hop
5-Business
Path
to
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Dr. Tracy Bradley Maples (Fall 2013)
Cost,1st
hop
7
CECS 474 COMPUTER NETWORKING INTEROPERABILITY
1-Data Center
Path
to
Cost,1st
hop
2-Engineering
Path
to
Cost,1st
hop
3-Mathematics
Path
to
Cost,1st
hop
4-Liberal Arts
Path
to
Cost,1st
hop
5-Business
Path
to
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
1-Data Center
2-Engineering
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
3-Mathematics
Path
to
Cost,1st
hop
4-Liberal Arts
Path
to
Cost,1st
hop
5-Business
Path
to
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
1-Data Center
2-Engineering
Path
to
Cost,1st
hop
Path
to
Cost,1st
hop
3-Mathematics
Path
to
Cost,1st
hop
4-Liberal Arts
Path
to
Cost,1st
hop
Cost,1st
hop
5-Business
Path
to
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
Dr. Tracy Bradley Maples (Fall 2013)
Cost,1st
hop
Cost,1st
hop
8