Three Router Static Route Practical Work
This practical work will be assessed by a quiz on the Moodle page for this course.
Objective
In this practical work, you will configure static routes between all three routers.This will allow your routers to route packets so that all routers and all hosts will be able to reach (ping) each other.
Once your configuration is complete, you will use basic techniques to test your network’s connectivity.
Scenario
Three separate classful networks need routing between them and their subnets.This will firstly be done using static routes, then by summarizing some of the networks and then using default routes.
Initial Questions:
- What are the different classful networks?
- Are there any subnets? If so, what are they?
Setup
- Draw a diagram of your proposed network including all details that are necessary to setup routing.
- Add 3 x 2811 routers to Packet Tracer workspace. You will need to add serial interfaces to each router.
- You do not need to use EXACTLY the same serial interfaces as shown on the diagram, but you do need to make a note of your choices on your diagram.
- Router1 should be named chatham
- Router2 should be named rochester
- Router3 should be named luton
- Add a 2950-24 switch to each router's Fa0/0 interface. No other configuration of the switch is needed.
- Configure the cabling as shown in the network diagram.
- Serial links should run at 1Mbps. Use the Router(config-if)#clock rate 1000000 command on the DCE end of the serial link to achieve this.
- Check that you have configured the serial interfaces correctly using the show controllers serial command for each serial interface. Check the third line of the output.
- Add one host PC to each switch. Give that PC the LOWEST available IP address (the next available after the Fa0/0 interface).
- Important! Configure the routers to include hostnames and the proper interface commands including IP addresses, subnet masks, etc.
- Each router should be able to ping the interface of the adjacent (neighbouring) router and the host on its LAN (FastEthernet) interface. Test and troubleshoot as necessary.
- Use the context sensitive help, previous labs, your books and /or handouts and if you are still having problems ask your partner or ask the instructor for assistance.
Step 1 – Configuring Static Routes
On each router configure a separate and specific static route for each network or subnet. You do not need to configure static routes for the router’s directly connected network(s) because like a host, by configuring the IP address and subnet mask on an interface tells the router that it belongs to that network/subnet.Router1
- chatham(config)# ip route 172.16.3.0 255.255.255.0 172.16.2.2
- chatham(config)# ip route 192.168.2.0 255.255.255.0 192.168.1.2
Router2
- rochester(config)# ip route 172.16.1.0 255.255.255.0 172.16.2.1
- rochester(config)# ip route 192.168.1.0 255.255.255.0 172.16.2.1
- rochester(config)# ip route 192.168.2.0 255.255.255.0 172.16.2.1
Router3
- luton(config)# ip route 172.16.1.0 255.255.255.0 192.168.1.1
- luton(config)# ip route 172.16.2.0 255.255.255.0 192.168.1.1
- luton(config)# ip route 172.16.3.0 255.255.255.0 192.168.1.1
Save your router configurations to NVRAM after every change using the write command or the copy running-config startup-config commands.
Verify and Validate:
- All hosts and all routers should be able to ping every interface in the network.
- Do a “show running-config” and notice the static routes that you entered.
- Router# show ip route
What routes to which networks are displayed?
Which routes are static and which routes are directly connected? - How can you tell the difference between Static routes and Directly connected networks?
What is the administrative distance for a static route?
What is the administrative distance for a directly connected network?
Questions:
- How does the next-hop-ip-address help with the routing process?
- Does it give the entire route, i.e., subnet mask?
- What is it actually doing regarding the routing of the packet?
- How does a packet get from Host 2 to Host 3?
- Instead of a next-hop-ip-address, what else could you have used?
- What would you need to do if you added new networks or deleted/modified existing networks to ensure routing to the new networks was possible from all points in the existing network?
- Is there any way to summarize several static routes to multiple subnets (destinations) into a single static route?
Outputs
rochester#show ip route
(Output omitted)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 3 subnets
S 172.16.1.0 [1/0] via 172.16.2.1
C 172.16.2.0 is directly connected, Serial0/0/0
C 172.16.3.0 is directly connected, FastEthernet0/0
S 192.168.1.0/24 [1/0] via 172.16.2.1
S 192.168.2.0/24 [1/0] via 172.16.2.1
(Output omitted)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 3 subnets
S 172.16.1.0 [1/0] via 172.16.2.1
C 172.16.2.0 is directly connected, Serial0/0/0
C 172.16.3.0 is directly connected, FastEthernet0/0
S 192.168.1.0/24 [1/0] via 172.16.2.1
S 192.168.2.0/24 [1/0] via 172.16.2.1
chatham#show ip route
(output omitted)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 3 subnets
C 172.16.1.0 is directly connected, FastEthernet0/0
C 172.16.2.0 is directly connected, Serial0/0/0
S 172.16.3.0 [1/0] via 172.16.2.2
C 192.168.1.0/24 is directly connected, Serial0/0/0
S 192.168.2.0/24 [1/0] via 192.168.1.2
luton#show ip route
(Output omitted)
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 3 subnets
S 172.16.1.0 [1/0] via 192.168.1.1
S 172.16.2.0 [1/0] via 192.168.1.1
S 172.16.3.0 [1/0] via 192.168.1.1
C 192.168.1.0/24 is directly connected, Serial0/0/0
C 192.168.2.0/24 is directly connected, FastEthernet0/0
Step 2 – Configuring Summary Static Routes
The configuration of the routers in Step 1 works well and is a valid way to configure routing on these networks.Earlier, you should have noticed that the network 172.16.0.0 is divided into several subnets.
Examine the routing table for luton.
luton does not really need 3 separate static routes for each subnet, since all of the 172.16.0.0 subnets can be reached via the same next-hop-ip-address, i.e. chatham.
Now we can reconfigure the static routes on luton so that it only uses a single static route to reach all of the 172.16.0.0 subnets.
Examine the routing tables for the other 2 routers and check whether there is a need to summarise repeated subnetworks/
It can be seen that these two routers do not require changes.
chatham
- No changes
rochester
- No changes
Router3
- First, remove the current static routes:
- luton(config)# no ip route 172.16.1.0 255.255.255.0 192.168.1.1
- luton(config)# no ip route 172.16.2.0 255.255.255.0 192.168.1.1
- luton(config)# no ip route 172.16.3.0 255.255.255.0 192.168.1.1
- Check the routing table for luton to ensure that the static routes have been removed.
- Now, add the new summary static route:
- luton(config)# ip route 172.16.0.0 255.255.0.0 192.168.1.1
Save your current configuration to NVRAM.
Verify and Validate:
- All hosts and all routers should be able to ping every interface in the network.
- Do a “show running-config” and notice the static routes that you entered.
- luton# show ip route
What routes to networks do you now see? - What difference do you notice in the subnet mask(s) for the new static route(s)?
Questions:
- What made this new summary static route work for all subnets?
- Why is a single summary static route an advantage regarding the size of the routing table?
- Why is a single summary static route an advantage regarding future changes to the 172.16.0.0 network?
Outputs
luton#show ip route
(Output omitted)
Gateway of last resort is not set
S 172.16.0.0/16 [1/0] via 192.168.1.1
C 192.168.1.0/24 is directly connected, Serial0/0/0
C 192.168.2.0/24 is directly connected, FastEthernet0/0
(Output omitted)
Gateway of last resort is not set
S 172.16.0.0/16 [1/0] via 192.168.1.1
C 192.168.1.0/24 is directly connected, Serial0/0/0
C 192.168.2.0/24 is directly connected, FastEthernet0/0
Step 3 – Configuring Default Static Routes
Both Step 1 and Step 2 are acceptable ways to configure routing for these networks. We notice that the 172.16.3.0/24 and the 192.168.2.0/24 networks are “stub networks,” meaning that there is only one way out (both via chatham).chatham
- No changes
rochester
- First, remove the current static routes:
- rochester(config)# no ip route 172.16.1.0 255.255.255.0 172.16.2.1
- rochester(config)# no ip route 192.168.1.0 255.255.255.0 172.16.2.1
- rochester(config)# no ip route 192.168.2.0 255.255.255.0 172.16.2.1
- Now, add the new default static route:
- rochester(config)# ip route 0.0.0.0 0.0.0.0 172.16.2.1
luton
- First, remove the current static routes:
- luton(config)# no ip route 172.16.0.0 255.255.0.0 192.168.1.1
- Now, add the new default static route:
- luton(config)# ip route 0.0.0.0 0.0.0.0 192.168.1.1
Verify and Validate:
- All hosts and all routers should be able to ping every interface in the network.
- Do a “show running-config” and notice the static routes that you entered.
- rochester# show ip route
What routes to which networks do you now see? - luton# show ip route
What routes to which networks do you now see?
Questions:
- Do you think static routes are still used even with dynamic routing (RIP, OSPF, etc.)?
Hint: Think about the administrative distance.
- Do you think default static routes are still used even with dynamic routing (RIP, OSPF, etc.)?
What is the disadvantage of doing this? - What is shown in the routing table to denote a default static route?
- How would a default static route be properly used in a real world network? (How would a company’s network use a default route when connecting to the Internet?)
Outputs
rochester#show ip route(Output omitted)Gateway of last resort is 172.16.2.2 to network 0.0.0.0
172.16.0.0/24 is subnetted, 2 subnets
C 172.16.2.0 is directly connected, Serial0/0/0
C 172.16.3.0 is directly connected, FastEthernet0/0
S* 0.0.0.0/0 [1/0] via 172.16.2.1
luton#show ip route
(Output omitted)
Gateway of last resort is 192.168.1.2 to network 0.0.0.0
C 192.168.1.0/24 is directly connected, Serial0/0/0
C 192.168.2.0/24 is directly connected, FastEthernet0/0
S* 0.0.0.0/0 [1/0] via 192.168.1.1
Save your current configuration to NVRAM.
Tidying your Network
When you have finished, you should add passwords to your routers. The options are to add a non-encrypted password (insecure) or an encrypted password to the router to keep unwanted personnel from entering privileged exec mode by configuring passwords of cisco to login to the router (console) and class to access the enable commands.
The syntax to make the enable password class is:
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#enable secret class
Router(config)#end
Do this for all routers in your network.
Add a message of the day - this can be a statement of your company policy regarding unauthorised access to digital resources perhaps - use your imagination to create a meaningful message.
Router(config)#banner motd "Authorised Access Only"
If you save your changes and logout of the router, the Message of the Day will appear before you login again.
All interfaces can be given descriptions. This helps when you are making changes to a router's configuration and are not familiar with the network's layout.
rochester#conf t
Enter configuration commands, one per line. End with CNTL/Z.
rochester(config)#int fa0/0
rochester(config-if)#description Second floor LAN
rochester(config-if)#end
Add descriptions that are meaningful to all interfaces in your network.
Save your work and the answers to all questions. you will need to refer back to this work to answer the quiz based on this practical work and also later in the course.
