Download Company Network

Company Network
Master Digital Media
Date: 11.11.2006
Company Network
Course
Networking (Mobile Networks and Security)
Prof. Dr. Richard Sethmann
University of Applied Sciences Bremen
Master Digital Media
Prof. Dr. Richard Sethmann
File:
Net_L6_Company_Network.doc
1/5
Master Digital Media
Date: 11.11.2006
Company Network
1. Fundamentals / Readings
Presentations:
• Company_Network.ppt
• MNS_1_Routing.ppt
Router commands: see CiscoPedia
Readings:
Topic
Subnetting
TCP/IP Transport Layer
Routing
NAT
Readings
CCNA 1 module 10
CCNA 1 module 11
CCNA 2 module 6 and 7
CCNP 1 module 3
CCNA 4 module 1
Example in CiscoPedia
see command:
ip nat inside source
Remark
2. Questions
These questions have to be answered at home before the lab.
1. What is the difference between private and public IP addresses?
2. Describe the functionality of NAT!
3. Divide the network 204.204.7.0 /28 into two subnets and write the network
address, broadcast address and the IP host ranges in a table.
4. What is a „Default Gateway“?
Prof. Dr. Richard Sethmann
File:
Net_L6_Company_Network.doc
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Master Digital Media
Date: 11.11.2006
Company Network
Fa0/0
S0/1
Fa0/0
Company R
NAT Router
Fa0/1
Center
Top
S0/0
ISP Router
Fa0/0
Bottom
Internet
ISP/Internet
Company Network
3. Topology
204.204.7.3
FTP
DNS
Mail
Web
210.93.105.201
192.168.0.101
DMZ Server
LAN PCs
Internet Server
NAT Router
FA0/0:
204.204.7.1
Company R
FA0/0: 204.204.7.4
FA0/1:
S0/1:
192.168.0.1
FTP
DNS
Mail
Web
ISP Router
FA0/0: 210.93.105.1
204.204.7.9
S0/0: 204.204.7.14
DNS Names:
dns_server.firma.de
mail_server.firma.de
dmz_server.firma.de
webserver.internet.de
Please fill out the following table:
LAN PCs
DMZ server
Internet server
IP address
Subnet mask
Default gateway
Prof. Dr. Richard Sethmann
File:
Net_L6_Company_Network.doc
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Company Network
Master Digital Media
Date: 11.11.2006
4. Tasks
Step 1:
Establish the physical connection according the topology.
Step 2:
Configure the IP addresses and default gateway on each PC. Deactivate all other
NICs on the PCs.
Step 3:
Configure the following on each router (NAT Router, Company Router and ISP
Router). Do not configure NAT at this time.
a.
b.
c.
d.
e.
f.
IP addresses with subnet mask (they are different)
Hostname
Passwords (cisco und class (secret))
Console (line console 0 ( login, Password: cisco)
Virtual Terminal (line vty 0 15)
Interfaces (Don’t forget: „no shutdown“ for the interfaces and clock
rate 64000 for the serial interfaces)
g. Static routes
Step 4:
Test the topology by pinging all interfaces from all devices.
Step 5:
Is it possible to ping internal PC from the ISP-PC?
Please explain why or why not.
Step 6:
Configure NAT on the NAT Router
Help: Example in CiscoPedia, see command “ip nat inside source” and use the
option “overload”
The following has to be configured:
ƒ Nat pool
ƒ Access list fort he internal IP addresses
ƒ Assign NAT to the interfaces
Step 7:
Test the topology by pinging all interfaces from all devices.
Verify the functionality of NAT by using Ethereal on the PCs and the “debug ip nat”
command on the NAT Router.
Step 7:
Save the router configurations.
Prof. Dr. Richard Sethmann
File:
Net_L6_Company_Network.doc
4/5
Company Network
Master Digital Media
Date: 11.11.2006
5. Evaluation
Discuss the results of the lab and answer the following questions.
These questions have to be answered at home after the lab.
1.
2.
3.
4.
5.
Why do we need a default gateway on the PCs?
Which transport layer protocol is used for DNS?
Why should NAT be used in a company network?
What is a NAT pool?
Why do we use access control lists for NAT?
Prof. Dr. Richard Sethmann
File:
Net_L6_Company_Network.doc
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