Chapter 7 MPLS Network Faults

BGP Process Down Alarm

The BGP Neighbor Loss alarm is detected actively by the system and service alarms are generated. The system also supports BGP neighbor down syslogs.

When the VNE BGP component polls the BGP neighbor status (expedite or normal polling) and finds an entry for a neighbor no longer exists or its state changed from Established to another state, the BGP component issues a BGP Neighbor Loss alarm. This alarm causes the BGP component to issue a Root Cause Analysis (RCA) correlation flow to find the root cause. If RCA does not find an alarm to correlate, the VNE sends the alarm to the gateway as a ticket.

If this alarm is configured in the registry to issue a Look For Affected flow. If a BGP neighbor loss occurs and the BGP component has no other BGP PE links, all VRFs with route entries to the PE as BGP next hops are true-affected. This information is sent as an update to the previous BGP Neighbor Loss alarm.

BGP Process Down Alarm

A Cisco ANA query checks the status of the BGP process when the VNE BGP component polls for the status and configuration of its BGP neighbors (expedite or normal polling). If the BGP process is not running, the VNE BGP component issues an BGP Process Down alarm. This alarm is always a ticket and does not try to correlate to other alarms. All the BGP Neighbors Down alarms issued in response to the BGP Process Down alarm and is correlated to the BGP Process Down ticket.

Broken LSP Discovered Alarm

The MPLS Black Hole Found alarm activates a backward flow on the specific untagged entry in order to traverse the full path of the LSPs passing through it. If Cisco ANA locates services (for example, VRFs, pseudowire tunnels) along this path that are using these LSPs, a Broken LSP Discovered alarm is issued. Such services can be found only on PE routers, and they can be found on more than one PE router. The source of the Broken LSP Discovered alarm is the PE router on which the service was discovered, and in many cases this router is different from the router that issued the MPLS Black Hole Found alarm.

Broken LSP Discovered alarms are correlated to the MPLS Black Hole Found alarm (except in the case of a black hole alarm due to a link down). The Broken LSP Discovered alarm is detected actively by the system, namely, service alarms are generated. An example of an MPLS black hole scenario follows.

In the network described in this example, the shortest path from PE2 to PE3 is PE2<->P2<->PE3. The link between P2 and PE3 is an MPLS link, meaning interfaces on both sides of the link are configured as MPLS interfaces. Also assume that for some reason, the MPLS configuration is incomplete or incorrect, namely:

Only one interface is configured as an MPLS interface.

The label distribution protocol is configured differently on both interfaces (protocol mismatch).

In this case, the label switching table on P2 and PE3 will have untagged entries for the LSPs between PE2 and PE3. If PE2 and PE3 have VPN services (for example VRFs and pseudowires), the outcome will be that the data flow between PE2 and PE3 will be affected.

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Cisco Systems 3.6.6 manual BGP Process Down Alarm, Broken LSP Discovered Alarm

3.6.6 specifications

Cisco Systems has continually evolved its networking solutions to address the demands of modern enterprises, with the introduction of the Cisco Systems 3.6.6 version being no exception. This version integrates cutting-edge technologies designed to enhance network performance, security, and management efficiency, catering to the increasingly complex needs of businesses across various sectors.

One of the standout features of Cisco Systems 3.6.6 is its enhanced support for automation and orchestration. This version incorporates advanced automation tools, allowing IT teams to deploy and configure network resources more rapidly and efficiently. With features such as Cisco DNA Center’s intent-based networking, organizations can streamline operations and reduce manual intervention, leading to quicker service delivery and reduced operational costs.

Security remains a top priority, and Cisco Systems 3.6.6 includes improved security protocols that help protect sensitive data and critical infrastructure. The integration of Cisco SecureX provides a unified view of security across the network, enabling organizations to respond to threats in real-time, manage vulnerabilities proactively, and maintain compliance with regulatory standards. The incorporation of machine learning and AI-driven analytics ensures that potential threats are identified and mitigated before they can escalate.

Interoperability is another key characteristic of version 3.6.6, allowing existing Cisco hardware and software to work seamlessly together. This flexibility ensures that enterprises can leverage their current investments while adopting newer technologies without the need for a complete overhaul of their existing network architecture.

Additionally, Cisco Systems 3.6.6 has enhanced support for IoT devices, integrating robust frameworks that enable organizations to manage and secure an increasing number of connected devices. With the proliferation of IoT in various industries, this feature is vital for maintaining efficiency and security, as it allows for better monitoring and control over the connected ecosystem.

In conclusion, Cisco Systems 3.6.6 embodies a comprehensive approach to modern networking challenges. Its emphasis on automation, advanced security features, interoperability, and IoT support positions it as a pivotal solution for businesses looking to enhance their operational capabilities and embrace digital transformation. As organizations worldwide adapt to an ever-evolving technological landscape, Cisco Systems 3.6.6 stands out as a reliable partner in navigating these complexities.