Resolving No Ongoing Label State in L2Circuit: Fixing Spoke Router Configuration Issues

L2Circuit, also known as Layer 2 Circuit or L2VPN, is a popular technology used in computer networking to establish a Layer 2 connection between two or more remote sites over a shared infrastructure, such as a service provider’s network. However, like any complex technology, L2Circuit is not immune to configuration issues, one of which is the “No Ongoing Label State” error. In this article, we will delve into the world of L2Circuit, explore the causes of this error, and provide a step-by-step guide on how to resolve it by fixing spoke router configuration issues.

Understanding L2Circuit and Its Components

Before we dive into the “No Ongoing Label State” error, it’s essential to understand the basics of L2Circuit and its components. L2Circuit is a Layer 2 VPN technology that allows multiple remote sites to be connected over a shared infrastructure, such as a service provider’s network. The main components of L2Circuit include:

• CE (Customer Edge) routers: These are the routers located at the customer’s premises.
• PE (Provider Edge) routers: These are the routers located at the service provider’s edge.
• P (Provider) routers: These are the routers located within the service provider’s network.

L2Circuit uses a combination of MPLS (Multiprotocol Label Switching) and LDP (Label Distribution Protocol) to establish a Layer 2 connection between the CE routers. The PE routers play a crucial role in establishing and maintaining the L2Circuit connection.

What is No Ongoing Label State Error?

The “No Ongoing Label State” error is a common issue that occurs in L2Circuit configurations. This error occurs when the PE router is unable to establish a label state with the CE router, resulting in a failure to establish the L2Circuit connection. The error message is usually displayed on the PE router and indicates that there is no ongoing label state for the specific L2Circuit connection.

Causes of No Ongoing Label State Error

The “No Ongoing Label State” error can be caused by several factors, including:

• Incorrect configuration on the PE or CE router.
• Mismatched label values between the PE and CE routers.
• Failure to establish an LDP session between the PE and CE routers.
• Insufficient resources, such as bandwidth or memory, on the PE or CE router.

Resolving No Ongoing Label State Error

To resolve the “No Ongoing Label State” error, you need to identify and fix the underlying cause. Here are the steps to follow:

Step 1: Verify Configuration

The first step is to verify the configuration on both the PE and CE routers. Ensure that the L2Circuit connection is properly configured, and the label values are matched on both routers. You can use the `show l2circuit` command to verify the configuration.

Step 2: Check LDP Session

The next step is to check the LDP session between the PE and CE routers. Ensure that the LDP session is established and active. You can use the `show ldp session` command to verify the LDP session.

Step 3: Verify Label Values

If the LDP session is established, verify that the label values are matched on both the PE and CE routers. You can use the `show l2circuit labels` command to verify the label values.

Step 4: Check Resources

If the label values are matched, check the resources, such as bandwidth and memory, on both the PE and CE routers. Ensure that there are sufficient resources to establish and maintain the L2Circuit connection.

Step 5: Fix Configuration Issues

If you identify any configuration issues, fix them accordingly. This may involve modifying the L2Circuit configuration, adjusting the label values, or allocating more resources to the PE or CE router.

Fixing Spoke Router Configuration Issues

In a hub-and-spoke topology, the spoke router is responsible for establishing the L2Circuit connection with the hub router. If the spoke router is not properly configured, it can lead to the “No Ongoing Label State” error. Here are the steps to fix spoke router configuration issues:

Step 1: Verify Spoke Router Configuration

Verify that the spoke router is properly configured to establish an L2Circuit connection with the hub router. Ensure that the L2Circuit connection is enabled, and the label values are matched on both the spoke and hub routers.

Step 2: Check LDP Session on Spoke Router

Check the LDP session on the spoke router to ensure that it is established and active. You can use the `show ldp session` command to verify the LDP session.

Step 3: Verify Label Values on Spoke Router

Verify that the label values are matched on both the spoke and hub routers. You can use the `show l2circuit labels` command to verify the label values.

Step 4: Fix Configuration Issues on Spoke Router

If you identify any configuration issues on the spoke router, fix them accordingly. This may involve modifying the L2Circuit configuration, adjusting the label values, or allocating more resources to the spoke router.

Conclusion

The “No Ongoing Label State” error is a common issue that occurs in L2Circuit configurations. By understanding the causes of this error and following the steps outlined in this article, you can resolve the issue and establish a stable L2Circuit connection. Remember to verify the configuration, check the LDP session, verify label values, and fix configuration issues on both the PE and CE routers, as well as the spoke router in a hub-and-spoke topology. By doing so, you can ensure a reliable and efficient L2Circuit connection.