Interview Questions for Juniper

Junos OS, Juniper Networks’ proprietary network operating system, distinguishes itself from others like Cisco IOS or Linux-based systems through its unique architecture and features. It’s built on a single, unified operating system that manages both routing and switching functions, unlike many systems that utilize separate OSes for each. This unified approach offers advantages in terms of simplification, management, and scalability.

One key difference is Junos OS’s reliance on a highly structured, hierarchical configuration system. It’s based on a declarative model, meaning you specify the desired state, and Junos manages the specifics of achieving it. This is unlike some other systems that may use a more procedural approach. This structured approach promotes consistency and reduces configuration errors. Another significant difference lies in Junos OS’s robust security features built-in from the ground up, encompassing various levels of access control and encryption. Finally, Junos OS is known for its flexibility and programmability, allowing for extensive customization through scripting and automation.

• Unified OS: Manages routing and switching within a single platform.
• Declarative Configuration: Focuses on ‘what’ instead of ‘how’, streamlining configuration.
• Robust Security: Integrated security features are designed to protect against many threats.
• Extensible via Scripting: Allows automation and customization through scripting languages like Python.

I have extensive experience working with Juniper MX Series routers, primarily in high-availability and large-scale deployments. I’ve configured and managed these routers in various enterprise and service provider networks, handling tasks ranging from basic configuration to advanced MPLS VPN implementation. For instance, I was involved in a project where we implemented a highly available MX960-based core network for a major telecommunications company, using features like Virtual Chassis and Junos’ advanced routing protocols to ensure seamless failover and optimal performance. This experience included working with various interface types, such as 10GE, 40GE, and 100GE, and implementing sophisticated Quality of Service (QoS) policies to prioritize critical traffic.

My responsibilities often included monitoring router performance, troubleshooting connectivity issues, and optimizing configurations for improved efficiency. I am adept at utilizing Junos OS commands to diagnose issues, analyze traffic patterns, and implement necessary changes. I’m also familiar with the MX Series’ advanced features such as carrier-grade NAT (CGNAT) and various Virtual Private Network (VPN) technologies, including IPSec and MPLS VPN.

I’m very familiar with Juniper EX Series Ethernet switches. My experience encompasses configuring and managing various models within both enterprise and data center environments. I’ve worked with features like Virtual Chassis, which allows for managing multiple EX Series switches as a single logical device, simplifying management and providing redundancy. I’ve also extensively used features like VLANs, spanning-tree protocols (RSTP, MSTP), and link aggregation (LAG) to build robust and scalable network infrastructures. In one project, we used EX Series switches to build a highly available network for a large university campus, encompassing wired and wireless connectivity. This involved configuring security features like MAC authentication bypass (MAB) and 802.1X authentication.

My troubleshooting experience with EX Series switches includes diagnosing link issues, resolving VLAN configuration problems, and resolving spanning tree issues. I’m proficient in using the Junos OS command-line interface (CLI) and analyzing switch logs to pinpoint and resolve problems. I also have experience monitoring switch performance using tools like Junos Space.

Junos Space Network Management is Juniper’s centralized management platform for their networking equipment. It provides a single pane of glass for monitoring, configuring, and managing various Juniper devices, including routers, switches, and security gateways. It simplifies network management by consolidating tasks that would otherwise require individual device access. The platform offers features such as automated provisioning, centralized configuration management, performance monitoring, and fault management. This helps to reduce operational complexity and improve efficiency.

My experience with Junos Space includes using it to monitor the health and performance of large-scale networks, proactively identify potential issues, and automate routine tasks such as software upgrades and configuration changes. I’ve found it particularly useful for visualizing network topology, analyzing traffic flows, and gaining insights into network performance. The dashboards are highly customizable, allowing for tailoring views to specific needs and reporting requirements. Its role-based access control also enhances security by allowing granular permissions for different users and groups.

Troubleshooting connectivity issues on a Juniper network involves a systematic approach. It begins with understanding the symptoms – is it a complete outage, intermittent connectivity, slow performance, or something else? The next step involves identifying the affected area of the network. This may involve checking interfaces, cables, and network devices using the Junos OS CLI. I would utilize various commands like show interfaces terse, show route, and show mpls forwarding-table to gain visibility into the network state.

Further diagnostic steps involve checking routing tables to verify that correct routes are learned and being used. Ping and traceroute tests can help to identify specific points of failure. Examining device logs is crucial for identifying errors or events that may have contributed to the connectivity problem. For instance, a significant drop in interface counters might point to a hardware or cabling issue. If the problem is related to a specific protocol, like BGP or OSPF, further analysis of the protocol’s configuration and state would be necessary. Tools like Junos Space can provide a consolidated view of the network, making it easier to spot potential issues.

This methodical approach, combined with a strong understanding of networking principles and Junos OS, is key to efficient troubleshooting. I always start with the most basic checks before moving on to more complex issues to save time and efficiently resolve the problem.

I have extensive experience configuring and troubleshooting BGP on Juniper devices. I’ve implemented BGP in various scenarios, from small-scale internal networks to large-scale service provider backbones. My experience includes configuring BGP attributes such as AS path, community lists, and route reflectors to manage route propagation and policy. I’ve worked with different BGP flavors, such as IBGP (Internal BGP) and EBGP (External BGP), and am proficient in diagnosing and resolving BGP convergence issues. For example, I’ve resolved issues related to BGP flapping, routing loops, and improper route filtering using the tools available within Junos OS.

A common troubleshooting technique involves examining the BGP neighbor status using the show protocols bgp neighbor command to verify that neighbors are established and exchanging routes correctly. Analyzing the BGP routing table using show route protocol bgp helps to understand the paths learned from different peers. I also use BGP logging extensively to identify events and errors that might be impacting routing. My experience also extends to implementing sophisticated BGP policies, for example, using route maps and AS path access lists to control route advertisements and filtering.

OSPF configuration and troubleshooting on Juniper routers involves understanding the protocol’s operation and the tools available within Junos OS. Configuring OSPF involves defining areas, specifying interfaces to include in OSPF, and configuring authentication if required. The configuration is hierarchical, making it well-structured and relatively easy to manage.

Example: A basic OSPF configuration on a Juniper router might look like this:
set protocols ospf area 0.0.0.0 interface ge-0/0/0.0
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 authentication-key secret password

Troubleshooting OSPF often involves verifying the OSPF neighbor relationships using the show protocols ospf neighbor command. This command provides information on the state of each neighbor, which is essential for identifying problems like adjacency issues. Examining the OSPF routing table with show route protocol ospf reveals the routes learned through OSPF. Discrepancies in the routing table or missing neighbors indicate potential issues with the configuration or network connectivity. Analyzing OSPF logs aids in identifying errors and events, providing valuable insights into the cause of any problems. I’ve used this methodology to resolve OSPF issues ranging from misconfigurations to network connectivity failures.

My familiarity with Juniper’s security features is extensive. I’ve worked extensively with their suite of security products, encompassing firewalls (SRX Series), intrusion prevention systems (IPS), VPN gateways, and unified threat management (UTM) solutions. My understanding goes beyond simply configuring these features; I grasp the underlying security principles and best practices for implementing robust security architectures. This includes a deep understanding of security policies, zone-based firewalls, application control, and threat intelligence integration.

For example, I’ve designed and implemented security policies that leverage features like application identification and control to restrict access to specific applications based on user roles and network segmentation, significantly improving network security posture.

My experience with Juniper SRX Series firewalls spans several years and encompasses various deployment models. I’m proficient in configuring and managing all aspects of these firewalls, from basic firewall rules to advanced features like VPNs, IPSec, and high-availability setups. I’m also experienced in troubleshooting performance issues and optimizing firewall rules for efficiency. I’ve worked with various SRX models, ranging from smaller branch office deployments to large enterprise-grade firewalls.

For instance, in a recent project, I migrated a client’s legacy firewall infrastructure to SRX Series devices, resulting in a 20% improvement in performance and a simplified management interface. This involved meticulous planning, phased migration, and rigorous testing to ensure minimal disruption to their network operations.

My VPN configuration experience on Juniper devices is comprehensive, covering both site-to-site and remote access VPNs. I’m adept at configuring various VPN protocols, including IPSec, L2TP, and SSL VPN. I understand the importance of key management, authentication mechanisms, and secure configuration practices to prevent vulnerabilities. I’ve worked with both CLI and Junos Space for configuration and management.

A specific example involved setting up a secure site-to-site VPN between two geographically dispersed offices using IPSec. This included configuring IKEv2, negotiating security associations (SAs), and implementing robust authentication and encryption mechanisms. The result was a secure and reliable connection between the two locations.

For remote access VPNs, I often leverage the SSL VPN capabilities of the SRX, providing secure access for remote users using web browsers without requiring specialized VPN clients, improving usability and accessibility.

Configuring a high-availability (HA) setup using Juniper devices typically involves deploying two devices in an active-passive or active-active configuration. The active device handles all traffic while the passive device monitors the active device’s status. In case of a failure, the passive device takes over seamlessly. This requires careful configuration of interfaces, routing protocols (like BGP or OSPF), and the HA feature itself using the Junos OS.

The process involves configuring control and data plane synchronization between the two devices, selecting an appropriate HA mode (active-passive or active-active), defining the failover criteria, and setting up heartbeat mechanisms. It’s crucial to test the HA setup regularly to ensure proper failover functionality. This is usually done through the Junos OS CLI, using commands to configure the HA group and monitor its status.

For example, set chassis cluster is a foundational command in establishing a cluster for HA.

My experience with Junos scripting includes both the Junos OS CLI and PyEZ. I’m proficient in writing scripts for automating tasks such as configuration backups, device configuration changes, and network monitoring. The Junos OS CLI provides a powerful command-line interface for configuration, while PyEZ offers a Python library for programmatic control of Juniper devices. I prefer PyEZ for more complex automation tasks due to its flexibility and integration with other Python libraries.

For example, I’ve developed a PyEZ script to automate the configuration of hundreds of Juniper routers with consistent settings, ensuring uniformity and reducing manual configuration errors, which is far more efficient than manually configuring each device.

Understanding the Junos OS hierarchical configuration model is crucial for effective scripting. Each command corresponds to a specific location in the configuration tree. This structure significantly impacts how configuration scripts are written and executed.

My experience with network automation using Juniper devices is significant. I’ve leveraged various tools and technologies for automating network management tasks, including Ansible, Junos Space, and custom Python scripts using PyEZ. This automation includes tasks such as device configuration, deployment, monitoring, and troubleshooting. It significantly improves efficiency, reduces operational errors, and allows for faster network provisioning and scalability.

A recent project involved automating the deployment of new Juniper EX switches to a large data center using Ansible. This included automating the configuration of VLANs, routing protocols, and security policies, significantly reducing deployment time from days to hours, while maintaining configuration consistency and accuracy.

My understanding of Quality of Service (QoS) on Juniper networks is comprehensive. QoS is crucial for prioritizing network traffic based on various criteria like application type, user priority, or bandwidth requirements. Juniper devices offer robust QoS features using class-of-service (CoS) and differentiated services (DiffServ) models. This involves defining traffic classes, assigning priorities, and implementing queuing mechanisms to manage bandwidth allocation effectively.

Implementing QoS often involves configuring traffic policing, shaping, and scheduling mechanisms. This allows network administrators to control the amount of bandwidth consumed by different types of traffic, guaranteeing sufficient bandwidth for critical applications while managing less critical traffic. The goal is to provide a better user experience and ensure that critical applications have the resources they need even under heavy network load.

For example, in a VoIP deployment, you might prioritize VoIP traffic over other traffic to ensure clear voice communication. This involves configuring QoS policies to mark VoIP traffic with a high priority and assigning it to a queue with higher bandwidth allocation.

Juniper’s Virtual Chassis technology allows you to manage multiple physical Juniper routers or switches as a single logical device. Imagine having several independent servers, but they all act as one cohesive unit. This simplifies management, providing a single point of control for configuration and monitoring. Instead of configuring each device individually, you manage them all through a single command-line interface or management system.

Benefits:

• Simplified Management: One CLI for multiple devices.
• High Availability: If one device fails, the others seamlessly take over.
• Increased Capacity: Combine the resources of multiple devices.
• Reduced Costs: Fewer management resources are needed.

Example: In a large data center, you might use Virtual Chassis to combine several EX Series switches into a single logical switch, providing significantly more ports and bandwidth than a single physical switch could offer. If one switch fails, the others continue to function, ensuring network uptime.

Traffic engineering on Juniper networks involves optimizing network paths to ensure efficient and reliable data flow. It’s like designing a highway system – you want to avoid congestion and ensure smooth traffic flow. This is achieved primarily through techniques like Constraint-Based Routing (CBR) and RSVP-TE (Resource Reservation Protocol – Traffic Engineering).

My experience includes configuring and troubleshooting RSVP-TE tunnels to provide dedicated bandwidth paths for critical applications, ensuring low latency and high reliability. I’ve also utilized MPLS (Multiprotocol Label Switching) and OSPF (Open Shortest Path First) in conjunction with TE to create robust and adaptable network paths. For example, I’ve used OSPF to advertise network topology and RSVP-TE to reserve bandwidth along a specific path chosen to avoid congestion in the network.

Example: Imagine a video conferencing application requiring guaranteed bandwidth. We would use RSVP-TE to reserve a specific amount of bandwidth along a pre-determined path, ensuring smooth and uninterrupted video calls even during periods of high network traffic.

Multicast routing on Juniper devices allows the efficient delivery of data streams to multiple recipients simultaneously. Think of it like a radio broadcast – a single transmission reaches many listeners. Protocols like PIM (Protocol Independent Multicast) – specifically PIM-SM (Sparse Mode) and PIM-DM (Dense Mode) – are commonly used on Juniper routers.

My experience encompasses configuring and troubleshooting PIM-SM and PIM-DM, including the use of RP (Rendezvous Point) in PIM-SM and the auto-discovery of multicast groups. I’ve also worked with multicast applications, such as video streaming and IP telephony, ensuring reliable multicast traffic delivery across the network. This involves careful configuration of interfaces, access lists and proper routing protocol integration.

Example: A large enterprise might use multicast to distribute video streams to multiple locations. PIM-SM would be an appropriate choice, using a centrally located RP to manage multicast traffic and reduce unnecessary traffic on the network.

Monitoring the health of a Juniper network involves a multi-faceted approach, leveraging both Juniper’s own tools and third-party solutions. It’s like having a comprehensive checkup for your network – checking vital signs to ensure everything is running smoothly.

Key methods:

• Junos OS CLI: Directly access routers and switches using the CLI to check interfaces, CPU utilization, memory usage, and routing table information. Commands like show interfaces, show system resources and show route are invaluable.
• Junos Space: This centralized management platform provides a graphical interface for monitoring multiple Juniper devices. You can view network performance, alarms, and topology maps all in one place.
• SNMP (Simple Network Management Protocol): Configure Juniper devices to send SNMP traps and provide data to network monitoring systems like Nagios or Zabbix. This provides real-time alerts and comprehensive network data.
• jflow/sFlow: These protocols provide granular network traffic analysis, offering insight into application behavior and potential bottlenecks.

By combining these tools, you can proactively identify and address network issues before they impact users or services.

Integrating network security monitoring tools with Juniper devices is crucial for a robust security posture. Think of it as installing security cameras and alarms in your network. I have experience with several tools.

Examples:

• Security Information and Event Management (SIEM) systems: Such as Splunk or QRadar, which can integrate with Juniper devices through syslog and SNMP to collect security logs and events. This provides central logging and analysis, enabling faster threat detection and response.
• Intrusion Detection/Prevention Systems (IDS/IPS): Juniper SRX firewalls provide integrated IDS/IPS capabilities. I have experience configuring and managing security policies, analyzing alerts, and tuning IPS to minimize false positives while effectively detecting malicious activity.
• Threat Intelligence Platforms: Integrating threat feeds into the Juniper security infrastructure to proactively block known malicious traffic.

Example: By correlating logs from Juniper devices with a SIEM, we can identify and respond to suspicious activity such as unauthorized access attempts or malware infections much quicker than by relying on individual device logs.

Juniper Contrail is a software-defined networking (SDN) solution that provides a virtualized and centralized network infrastructure. It’s like having a central control panel for your entire network. It simplifies network management and automation, providing dynamic scaling and improved visibility.

My experience with Contrail includes deploying and configuring virtual networks, implementing network policies, managing virtual routers and switches, and troubleshooting connectivity issues within the virtualized network infrastructure. This includes understanding Contrail’s various components such as the vRouter, the control node and the analytics node.

Example: In a cloud environment, Contrail would enable automated provisioning of virtual networks, simplifying the deployment of new applications and ensuring consistent network configurations across all virtual machines.

MAC address learning and forwarding is the foundation of Layer 2 switching. It’s how switches learn which devices are connected to which ports. Imagine it like a switchboard operator who learns which person is on which line. When a frame arrives, the switch checks its MAC address table. If it knows the destination MAC, it forwards the frame directly to the appropriate port. If not, it floods the frame to all ports except the receiving port.

Process: When a switch receives a frame, it extracts the source MAC address and learns the port that the device is connected to. This information is stored in a MAC address table. The switch then checks its MAC table to determine the port to forward the frame to based on the destination MAC address.

Juniper specifics: Juniper switches utilize efficient MAC address learning algorithms to optimize performance and scalability. Features like MAC address aging (automatic removal of inactive MAC addresses from the table) contribute to a robust and efficient Layer 2 switching environment. The show mac address-table command in the Junos OS CLI provides visibility into the MAC address table on a Juniper switch.

Capacity planning for a Juniper network involves predicting future bandwidth, processing power, and storage needs to ensure the network can handle increasing traffic and maintain performance. It’s like planning for a growing city – you need to anticipate the needs of its expanding population.

• Traffic Forecasting: Analyze historical network traffic patterns using tools like Juniper’s own analytics platforms (discussed later) to project future bandwidth requirements. Consider growth factors like new applications, increased users, and changes in user behavior.
• Device Sizing: Based on the traffic forecast, choose Juniper routers and switches with sufficient capacity (bandwidth, processing power, number of interfaces). Over-provisioning is better than under-provisioning, but finding the right balance is key to avoiding unnecessary costs.
• Link Aggregation: Employ link aggregation (LAG) to bundle multiple physical links into a single logical link, increasing bandwidth and providing redundancy. This is like having multiple roads leading into the city to manage traffic efficiently.
• QoS Planning: Implement Quality of Service (QoS) policies to prioritize critical traffic, ensuring that even during peak times, vital services remain responsive. This is similar to assigning priority lanes to emergency vehicles.
• Regular Monitoring: Continuously monitor network performance using tools like Junos Space or other monitoring solutions to identify potential bottlenecks and adjust capacity plans proactively. Regular monitoring ensures the city’s infrastructure is operating smoothly.

For example, if historical data shows a steady 10% yearly increase in bandwidth usage, I would project this growth into the future and select devices with capacity exceeding the projected needs for at least the next three to five years.

Troubleshooting routing protocols on Juniper, particularly migration scenarios from other vendors, requires a strong understanding of both Juniper’s Junos OS and the protocols themselves. I’ve extensively worked with both EIGRP and IS-IS migrations.

EIGRP: While Juniper doesn’t natively support EIGRP, a migration often involves replacing EIGRP with OSPF or BGP. This necessitates a careful mapping of AS numbers, network segments, and redistribution configurations. We would need to analyze the EIGRP topology, identify the key routes, and then configure the equivalent OSPF or BGP configuration on the Juniper devices. Careful attention is needed during the cutover phase to minimize disruption.

IS-IS: Migrating from another vendor’s IS-IS implementation to Juniper’s is relatively straightforward as both typically use the same underlying IS-IS protocol. However, attention needs to be paid to the nuances of configuration, such as the IS-IS level (Level 1 or Level 2), MTU sizes, and authentication. Testing using tools like ping and traceroute between the legacy and Juniper networks is crucial during the migration.

A real-world example involved migrating a large enterprise from a Cisco network using EIGRP to a Juniper network using OSPF. We painstakingly mapped the Cisco EIGRP configuration to its OSPF equivalent on Juniper routers, meticulously testing each step to ensure seamless transition. This required thorough understanding of both routing protocols and expertise in Junos configuration commands.

IPv6 configuration on Juniper devices is managed using Junos OS commands, and it’s quite straightforward. The process involves defining IPv6 interfaces, configuring IPv6 routing protocols (like OSPFv3 or BGP), and implementing necessary security features.

• Interface Configuration: Assigning IPv6 addresses to interfaces is similar to IPv4, using commands like set interfaces ge-0/0/0 unit 0 family inet6 address 2001:db8::1/64
• Routing Protocols: Configuring OSPFv3 or BGP for IPv6 routing involves specifying the IPv6 address family within the routing protocol configuration. For example, within an OSPFv3 configuration, you would specify the IPv6 network segments.
• IPv6 Firewall Filters: Security is paramount. Firewall filters can be configured to control IPv6 traffic flow, ensuring only authorized traffic is allowed.
• Neighbor Discovery Protocol (NDP): Understanding and configuring NDP, which handles address resolution in IPv6, is essential for proper IPv6 communication.

A common scenario is enabling dual-stack (IPv4 and IPv6) connectivity on an existing network. This involves configuring both IPv4 and IPv6 addresses on interfaces and ensuring that routing protocols support both address families. Thorough testing is crucial to confirm that applications work seamlessly with both address families.

I am very familiar with Juniper’s network analytics and reporting tools. Junos Space is a comprehensive platform that provides real-time monitoring, performance analysis, and reporting capabilities for Juniper networks. It allows for proactive identification of potential problems and provides historical data for trend analysis. I’ve extensively used Junos Space to:

• Monitor network health: Track device CPU usage, memory utilization, interface statistics, and routing protocol convergence.
• Analyze network performance: Identify bottlenecks and performance issues by analyzing traffic flows, latency, and packet loss.
• Generate reports: Create customized reports on network performance, security events, and capacity utilization for various stakeholders.
• Troubleshoot network issues: Use the detailed information provided by Junos Space to pinpoint the root cause of network problems.

Beyond Junos Space, I have experience using other tools that integrate with Juniper devices, allowing for broader network visibility and reporting. These tools often provide automated alerting and reporting features, helping to ensure proactive network management.

Implementing and managing Juniper security policies involves configuring various security features within Junos OS. This ranges from basic access control lists (ACLs) to more advanced features like intrusion prevention systems (IPS) and VPNs. My experience includes:

• Firewall Filters: Creating and managing firewall filters to control traffic flow based on source and destination IP addresses, ports, and protocols. This is the foundation of network security.
• Security Zones: Defining security zones to segment the network into trusted and untrusted areas. This is crucial for network segmentation and protection.
• VPN Configuration: Setting up VPN tunnels using protocols like IPsec or SSL to secure remote access and inter-site connectivity. Ensuring proper authentication and encryption is vital.
• Intrusion Detection/Prevention: Implementing Juniper’s security features to detect and mitigate malicious activity. This requires regular updates and tuning of the security policies.

For example, I recently implemented a multi-layered security approach for a client involving firewall filters, security zones, and IPsec VPNs to protect their network from external threats. Regular security audits and policy updates are crucial to maintaining a strong security posture.

Migrating from Cisco to Juniper networks requires a methodical approach that involves careful planning, configuration, and testing. Key aspects of this process include:

• Topology Mapping: Carefully map the existing Cisco network topology to understand the routing protocols, network segmentation, and security policies.
• Protocol Conversion: Translate Cisco’s proprietary protocols (where applicable) to their Juniper equivalents. For example, EIGRP might be replaced with OSPF or BGP.
• Configuration Translation: Migrate the Cisco configuration to Juniper Junos OS configuration using appropriate command-line interface (CLI) commands or automated tools where possible. Manual translation often requires significant expertise.
• Testing and Validation: Thoroughly test the migrated network to ensure connectivity, performance, and security are maintained or improved.
• Phased Migration: Implement a phased migration approach, transitioning segments of the network gradually to minimize disruption.

I’ve led several successful migrations, always emphasizing a gradual and carefully monitored transition. This includes thorough documentation, cross-team collaboration, and a detailed testing plan to mitigate risks and ensure a smooth transition for the end users.

Handling a network outage caused by a Juniper device failure requires a systematic approach that combines immediate action with long-term preventative measures.

• Identify the Problem: Quickly determine the failed device and the extent of the outage using monitoring tools. Junos Space or SNMP monitoring will be crucial here.
• Implement Failover Mechanisms: Utilize redundancy mechanisms like link aggregation (LAG), VRRP, or HSRP to automatically fail over to backup devices. Proper configuration of these features beforehand is essential.
• Isolate the Problem: If automatic failover doesn’t occur, isolate the failed device to prevent further spread of the outage. This may involve manually switching to redundant links or disabling affected interfaces.
• Repair or Replace: Repair the failed device or replace it with a spare. If the issue is hardware-related, a replacement will be faster.
• Restore Services: Bring the affected network segments back online and verify service restoration using appropriate tools (ping, traceroute).
• Root Cause Analysis: After restoring services, perform a root cause analysis to prevent future occurrences. Analyze logs, device health metrics, and environmental factors to identify and address underlying issues.

Imagine a highway closure – we need to quickly reroute traffic, repair the damaged section of the road, and then investigate the cause of the closure to prevent similar incidents in the future. A similar approach is needed when dealing with a Juniper device failure.