Config Lab: IPv6 Static Routes 2
IPv6 routing has many similarities with IPv4 routing; however, the length of the IPv6 addresses can sometimes get in the way of learning the main concepts. This next lab removes those barriers with a straightforward IPv6 static route configuration lab. All the IPv6 addresses and subnets are purposefully short (when abbreviated). Enjoy!
The Lab Exercise
Requirements
This lab uses a network topology with four routers and five IPv6 subnets. Each router connects to two subnets. Your job: add static IPv6 routes so that all routers have routes to all five IPv6 subnets, and that all the PCs in the figure can ping each other. The specific rules for this lab are:
- None of the routers use a dynamic routing protocol.
- Use global unicast addresses as next-hop, rather than link local addresses.
- Assumptions:
Figure 1: Four Routers and Five Switches
Initial Configuration
Examples 1, 2, 3, and 4 show the beginning configuration state of R1, R2, R3, and R4. All five switches are layer 2 switches with all default configuration, which places all interfaces on the same switch into VLAN1.
hostname R1
!
ipv6 unicast-routing
!
interface GigabitEthernet0/1
ipv6 address 2000::1/64
no shutdown
!
interface GigabitEthernet0/2
ipv6 address 2001::1/64
no shutdownExample 1: R1 Config
hostname R2
!
ipv6 unicast-routing
!
interface GigabitEthernet0/1
ipv6 address 2000::2/64
no shutdown
!
interface GigabitEthernet0/2
ipv6 address 2002::1/64
no shutdownExample 2: R2 Config
hostname R3
!
ipv6 unicast-routing
!
interface GigabitEthernet0/1
ipv6 address 2000::3/64
no shutdown
!
interface GigabitEthernet0/2
ipv6 address 2003::1/64
no shutdownExample 3: R3 Config
hostname R4
!
ipv6 unicast-routing
!
interface GigabitEthernet0/1
ipv6 address 2000::4/64
no shutdown
!
interface GigabitEthernet0/2
ipv6 address 2004::1/64
no shutdownExample 4: R4 Config
Answer Options - Click Tabs to Reveal
You can learn a lot and strengthen real learning of the topics by creating the configuration – even without a router or switch CLI. In fact, these labs were originally built to be used solely as a paper exercise!
To answer, just think about the lab. Refer to your primary learning material for CCNA, your notes, and create the configuration on paper or in a text editor. Then check your answer versus the answer post, which is linked at the bottom of the lab, just above the comments section.
You can also implement the lab using the Cisco Packet Tracer network simulator. With this option, you use Cisco’s free Packet Tracer simulator. You open a file that begins with the initial configuration already loaded. Then you implement your configuration and test to determine if it met the requirements of the lab.
(Use this link for more information about Cisco Packet Tracer.)
Use this workflow to do the labs in Cisco Packet Tracer:
- Download the .pkt file linked below.
- Open the .pkt file, creating a working lab with the same topology and interfaces as the lab exercise.
- Add your planned configuration to the lab.
- Test the configuration using some of the suggestions below.
You can also implement the lab using Cisco Modeling Labs – Personal (CML-P). CML-P (or simply CML) replaced Cisco Virtual Internet Routing Lab (VIRL) software in 2020, in effect serving as VIRL Version 2.
If you prefer to use CML, use a similar workflow as you would use if using Cisco Packet Tracer, as follows:
- Download the CML file (filetype .yaml) linked below.
- Import the lab’s CML file into CML and then start the lab.
- Compare the lab topology and interface IDs to this lab, as they may differ (more detail below).
- Add your planned configuration to the lab.
- Test the configuration using some of the suggestions below.
Download this lab’s CML file!
Network Device Info:
Interfaces used in CML match the interfaces used in the Lab topology.
Host device info:
The CML topology matches the lab topology.
| Device | IP Address | Mac Address | User/password |
| PC1 | 2001::100/64 | 02:00:11:11:11:11 | cisco/cisco |
| PC2 | 2002::100/64 | 02:00:22:22:22:22 | cisco/cisco |
| PC3 | 2003::100/64 | 02:00:33:33:33:33 | cisco/cisco |
| PC4 | 2004::100/64 | 02:00:44:44:44:44 | cisco/cisco |
Lab Answers Below: Spoiler Alert
Lab Answers: Configuration (Click Tab to Reveal)
Answers
Figure 1: Four Routers and Five Switches
ipv6 route 2002::/64 2000::2
ipv6 route 2003::/64 2000::3
ipv6 route 2004::/64 2000::4Example 1: R1 Config
ipv6 route 2001::/64 2000::1
ipv6 route 2003::/64 2000::3
ipv6 route 2004::/64 2000::4Example 2: R2 Config
ipv6 route 2001::/64 2000::1
ipv6 route 2002::/64 2000::2
ipv6 route 2004::/64 2000::4
Example 3: R3 Config
ipv6 route 2001::/64 2000::1
ipv6 route 2002::/64 2000::2
ipv6 route 2003::/64 2000::3Example 4: R4 Config
Commentary, Issues, and Verification Tips (Click Tabs to Reveal)
Commentary
When configuring static routes, it is important to ensure that you have all of the correct IP subnet information because just a small difference in subnet mask can make a big difference in routing behavior.
For this lab, you were tasked with configuring static routes between the routers so that each of their LANs would be able to route packets to each other. Because there are four different routes in this topology, this means that there will be three remote LAN subnets that need to have routes configured per router.
For R1 the three remote LAN subnets are: 2002::/64, 2003::/64 and 2004::/64. The first route would be for R2’s LAN subnet. R1 and R2 both connect to the subnet between the routers (the 2000::/64 subnet) and R2’s IPv6 address on this subnet is 2000::2, making this address the next-hop address in the static route. The complete command to configure this static route would be be ipv6 route 2002::/64 2000::2.
Note that the ipv6 route command could have used a link-local address as the next-hop address. However, the lab specifically asked you to use global unicast addresses instead of link local addresses as the next-hop address.
R1’s second static route, for the subnet off R3’s G0/2 interface, would use R3’s IPv6 address on this shared LAN of 2000::3. The complete command to configure this static route would be be ipv6 route 2003::/64 2000::3.
R1’s third and final route would a route to the subnet off R4’s G0/2 interface. R1’s next-hop address would be R4’s IPv6 address on the central LAN (2000::4). The complete command to configure this static route would be ipv6 route 2004::/64 2000::4.
The routes configured on R2, R3, and R4 follow similar logic. On all of the routers, the route for 2001::/64 (off R1) points to R1’s 2000::1 address as the next-hop address. On all routers, the route for 2002::/64 (off R2) points to R2’s 2000::2 address as the next-hop address. On all routers, the route for 2003::/64 (off R3) points to R3’s 2000::3 address as the next-hop address. And you guessed it, on all routers, the route for 2004::/64 (off R4) points to R4’s 2000::4 address as the next-hop address.
Known Issues in this Lab
This section of each Config Lab Answers post hopes to help with those issues by listing any known issues with Packet Tracer related to this lab. In this case, the issues are:
| # | Summary | Detail |
| 1 | None | No known issues related to this lab. |
Why Would Cisco Packet Tracer Have Issues?
(Note: The below text is the same in every Config Lab.)
Cisco Packet Tracer (CPT) simulates Cisco routers and switches. However, CPT does not run the same software that runs in real Cisco routers and switches. Instead, developers wrote CPT to predict the output a real router or switch would display given the same topology and configuration – but without performing all the same tasks, an actual device has to do. On a positive note, CPT requires far less CPU and RAM than a lab full of devices so that you can run CPT on your computer as an app. In addition, simulators like CPT help you learn about the Cisco router/switch user interface – the Command Line Interface (CLI) – without having to own real devices.
CPT can have issues compared to real devices because CPT does not run the same software as Cisco devices. CPT does not support all commands or parameters of a command. CPT may supply output from a command that differs in some ways from what an actual device would give. Those differences can be a problem for anyone learning networking technology because you may not have experience with that technology on real gear – so you may not notice the differences. So this section lists differences and issues that we have seen when using CPT to do this lab.
Beyond comparing your answers to this lab’s Answers post, you can test in Cisco Packet Tracer (CPT) or Cisco Modeling Labs (CML). In fact, you can and should explore the lab once configured. For this lab, once you have completed the configuration, try these verification steps.Â
- Connect to the command line of each of the PCs and attempt to ping the other PCs. If each of the static routes was configured correctly, everyone should have connectivity to each other.
- Use an extended ping command to ping from each router’s G0/2 interface to each router’s G0/2 interface IP address. For instance, from R1, the command ping 2004::1 source 2001::1 would test the forward route to R4’s G0/2 subnet and the reverse route back to R1’s G0/2 subnet.
- Try the traceroute6 command on each PC, referencing another PC’s address, to see the various next-hop IPv6 addresses.
I love the KISS principle. R1 g0/2 = 2000::1, R2 g0/2 = 2000::2, R3 g0/2 = 2000::3, R4 g0/2 = 2000::4. Thanks!
Yeah, if you look at the examples throughout my books, you’ll typically see the patterns for router numbers in the IPv4 and IPv6 addresses… just too many details to remember when studying without some helps like that!