Networking 101

Copyright Priscilla Oppenheimer

Lab 7 IP Addressing and Routing

Scenario

You are a senior network administrator working at a large company. The network engineers at headquarters have sent you some Cisco routers, firewalls, and switches to install. Your college intern has completed the cabling and your junior network administrator has checked the intern's work. You now have the job of getting IP addressing and routing working on all the devices, including the workstations, routers, firewalls, and switches.

Addressing Steps

  1. Power on the workstations, routers, switches, and firewalls.
  2. Configure the workstations for correct IP addressing information. (See the "Lab Topology and Addresses" drawing.)
    1. On Windows, use the Network Connections Control Panel.
    2. On Linux:
      1. Start the Console to get to a command line prompt.
      2. Type yast to get into Yet Another System Tool.
  3. To configure the routers and switches for the correct IP address start a HyperTerminal session.
  4. Type enable (followed by Enter). Type the enable password, provided by the instructor.
  5. Type configure terminal, which means you are configuring the device from a terminal. (Your PC acts as a terminal.)
  6. On the routers:
    1. Type interface and the interface type and number, for example interface fa0 or interface fa0/0. Press Enter.
    2. Type the IP address and subnet mask using the ip address <address> <mask> command. Press Enter.
    3. Be sure to do all interfaces.
  7. On the switch:
    1. Type interface vlan 1. Press Enter.
    2. Type the IP address and subnet mask using the ip address <address> <mask> command. Press Enter.
  8. On the PIX firewalls
    1. Type ip address outside followed by the ip address for e0 and the subnet mask. Press Enter.
    2. Type ip address inside followed by the ip address for e1 and the subnet mask. Press Enter.
  9. Type exit to get out of configuration mode.
  10. Test the new IP addresses using Ping.
  11. If you can ping other devices in your subnet, continue to Routing Steps. Otherwise do some troubleshooting. Ask for help if you need it.

Routing Steps

On the "real" routers, we'll use the Open Shortest Path First (OSPF) routing protocol, which is a dynamic link-state routing protocol. Then we'll add a default route for reaching networks outside our control. Neither the switch nor the PIX firewall is a "real" router so if you are on one of those, your job will be different.

Switch

  1. The switch is a Data-Link layer device so technically doesn't care about IP addressing and routing. However, if you want to ping it or Telnet to it, then it needs an IP address and a "default gateway," just like your PCs do. To configure the switch's default gateway, you need to be in config mode, and then you can use the following command.
    1. ip default-gateway <address of the gateway>
    2. For the address of the gateway, use the fa0/0 address of one of the 2600 routers.
    3. Test your change by seeing if you can ping the switch or Telnet to it from a PC.

PIX firewalls

  1. Firewalls don't usually run a routing protocol. They just send all traffic to a "real" router. So, on the PIX firewalls, you need to configure a default route. PIX B will also need a set of static routes. Get into config mode, and then use the following commands:
    1. Default route: route outside 0.0.0.0 0.0.0.0 <address of closest outside router> 1
    2. Static routes for PIX B: route inside <network number> 255.255.255.0 <address of inside router> 1

Routers

  1. You need to be in config mode if you aren't already.
  2. Enter the following OSPF commands:
    1. router ospf 1
    2. network 192.168.0.0 0.0.255.255 area 0
  3. Type exit to get out of configuration mode.
  4. Do some testing with Ping. You should be able to get to most of our subnets, but not to the Internet or PIX-only-attached networks.
  5. To reach the Internet, we will need a default route.
    1. Get into config mode and enter the following command:
      1. ip route 0.0.0.0 0.0.0.0 <address of router>
      2. For the address of the router use your "next-hop" router.
        1. On the 2600s, use the inside (e1) address of PIX B.
        2. On the 1700s, use your local 2600 router.
  6. To reach network 192.168.100.2, which is hanging off of PIX C, add the following commands to the 1700A router:
    1. ip route 192.168.100.0 255.255.255.0 192.168.40.2
    2. router ospf 1
      redistribute static

Reflection

What were the work goals of this project? (Please write this as if you were writing a work status report. In other words, write the project goals, not the learning objectives.) __________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

What problems did you encounter?

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

What concerns do you have for the future for this network? Assume that you and your co-workers will now have the job of operating and monitoring this new "real-life" network. Based on your experiences setting it up and any problems encountered, what will you be keeping an eye on? What problems may occur?

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________

__________________________________________________________________________________________________________