- What is routing?
- Scope of Answer: Explain the basic concept, emphasizing the process of selecting paths in a network along which to send data packets.
- Key Points: Path selection, data packet forwarding, network topology.
- What is the difference between static and dynamic routing?
- Scope of Answer: Highlight the manual configuration of static routes versus the automatic updating of routes in dynamic routing.
- Key Points: Manual configuration, automatic updates, routing protocols.
- Explain how distance-vector routing protocols work.
- Scope of Answer: Detail the use of algorithms like Bellman-Ford and the periodic sharing of routing tables between neighbors.
- Key Points: Bellman-Ford algorithm, routing tables, periodic updates.
- What are link-state routing protocols?
- Scope of Answer: Discuss the Dijkstra algorithm, how routers have a complete view of the network, and the use of LSAs (Link-State Advertisements).
- Key Points: Dijkstra algorithm, complete network view, LSAs.
- Describe OSPF (Open Shortest Path First).
- Scope of Answer: Mention areas, LSAs, OSPF states, and the use of cost as a metric.
- Key Points: Areas, LSAs, OSPF states, cost metric.
- What is BGP (Border Gateway Protocol)?
- Scope of Answer: Explain its use in the internet backbone, path vector protocol nature, and attributes like AS-PATH, NEXT-HOP.
- Key Points: Internet backbone, path vector protocol, AS-PATH, NEXT-HOP.
- How does RIP (Routing Information Protocol) work?
- Scope of Answer: Discuss its use of hop count as a metric, maximum hop count limit, and updates every 30 seconds.
- Key Points: Hop count metric, max hop count, periodic updates.
- What is EIGRP (Enhanced Interior Gateway Routing Protocol)?
- Scope of Answer: Mention DUAL algorithm, combination of distance-vector and link-state features, and unequal cost load balancing.
- Key Points: DUAL algorithm, distance-vector and link-state, unequal cost load balancing.
- How do routing tables get updated?
- Scope of Answer: Explain the process through which routers learn about new networks and update their routing tables accordingly.
- Key Points: Route learning, routing table updates, routing protocols.
- What is a default route?
- Scope of Answer: Discuss its use as a gateway of last resort when no other route matches the destination IP.
- Key Points: Gateway of last resort, default route usage.
- Explain the concept of route summarization.
- Scope of Answer: Highlight the reduction of routing table size and the process of consolidating multiple routes into a single advertisement.
- Key Points: Routing table size reduction, route consolidation.
- What are route redistribution and its use cases?
- Scope of Answer: Discuss connecting different routing domains and the potential for routing loops.
- Key Points: Connecting routing domains, routing loops.
- How does a router handle multiple routes to the same destination?
- Scope of Answer: Explain administrative distance and metric values in selecting the best route.
- Key Points: Administrative distance, metric values, best route selection.
- What is MPLS (Multiprotocol Label Switching)?
- Scope of Answer: Discuss the concept of labels, LER (Label Edge Routers), and LSR (Label Switch Routers).
- Key Points: Labels, LER, LSR.
- How do you configure a static route on a Cisco router?
- Scope of Answer: Detail the syntax and process, e.g., ip route [destination network] [mask] [next-hop address].
- Key Points: Static route configuration, Cisco commands.
- Explain split horizon in distance-vector routing.
- Scope of Answer: Discuss the prevention of routing loops and the rule that a router should not advertise a route back in the direction from which it came.
- Key Points: Routing loop prevention, split horizon rule.
- What is route poisoning?
- Scope of Answer: Describe the method of preventing routing loops by setting an infinite metric for a failed route.
- Key Points: Routing loop prevention, infinite metric.
- Explain the concept of an autonomous system (AS).
- Scope of Answer: Highlight the administrative domain of a network and the use of AS numbers in BGP.
- Key Points: Administrative domain, AS numbers, BGP.
- What are route flaps?
- Scope of Answer: Discuss the concept of a route frequently changing state, causing instability in the network.
- Key Points: Route instability, frequent state changes.
- How does policy-based routing work?
- Scope of Answer: Explain the use of criteria other than destination IP to make routing decisions, such as source IP or application type.
- Key Points: Routing criteria, source IP, application type.
- What is an area in OSPF?
- Scope of Answer: Discuss the hierarchical design of OSPF, the backbone area (Area 0), and other area types.
- Key Points: Hierarchical design, backbone area, OSPF areas.
- What is an adjacency in OSPF?
- Scope of Answer: Explain the relationship between OSPF routers that have exchanged hello packets and established a neighbor relationship.
- Key Points: OSPF neighbors, hello packets, adjacency.
- How does BGP use route attributes?
- Scope of Answer: Discuss attributes like weight, local preference, and AS path in making routing decisions.
- Key Points: Route attributes, weight, local preference, AS path.
- What are BGP peers?
- Scope of Answer: Explain the concept of BGP neighbors exchanging routing information and the establishment of a BGP session.
- Key Points: BGP neighbors, routing information exchange, BGP session.
- How does EIGRP calculate its metric?
- Scope of Answer: Detail the composite metric using bandwidth, delay, reliability, load, and MTU.
- Key Points: Composite metric, bandwidth, delay, reliability, load, MTU.
- What is a routing protocol’s convergence time?
- Scope of Answer: Explain the time it takes for routers to update their routing tables and reach a consistent state.
- Key Points: Convergence time, routing table updates, network consistency.
- Describe the concept of an edge router.
- Scope of Answer: Discuss routers that connect an internal network to external networks or the internet.
- Key Points: Edge router functions, internal to external network connection.
- What is an interior gateway protocol (IGP)?
- Scope of Answer: Mention protocols like OSPF, RIP, and EIGRP used within an autonomous system.
- Key Points: IGP protocols, OSPF, RIP, EIGRP.
- What is an exterior gateway protocol (EGP)?
- Scope of Answer: Highlight protocols like BGP used between autonomous systems.
- Key Points: EGP protocols, BGP, autonomous systems.
- Explain the process of route aggregation.
- Scope of Answer: Discuss combining several routes into a single advertisement to simplify routing tables.
- Key Points: Route aggregation, simplified routing tables.
- What is a floating static route?
- Scope of Answer: Describe a static route with a higher administrative distance than a dynamic route, used as a backup.
- Key Points: Floating static route, backup route, administrative distance.
- How does OSPF handle network changes?
- Scope of Answer: Discuss the immediate sending of LSAs to inform all routers about the change and recalculating the shortest path.
- Key Points: Network changes, LSAs, shortest path recalculation.
- What is a stub area in OSPF?
- Scope of Answer: Explain the concept of limiting external route advertisements to reduce routing overhead.
- Key Points: Stub area, external route limitation, routing overhead.
- How do routers use metrics in making routing decisions?
- Scope of Answer: Detail different metrics like hop count, bandwidth, delay, reliability, and their impact on route selection.
- Key Points: Routing metrics, hop count, bandwidth, delay, reliability.
- What is a link-state advertisement (LSA)?
- Scope of Answer: Describe the packets exchanged by OSPF routers to share information about network topology.
- Key Points: LSAs, OSPF routers, network topology.
- What is administrative distance in routing?
- Scope of Answer: Explain the ranking of route sources to determine the best path when multiple routes are available.
- Key Points: Administrative distance, route ranking, best path selection.
- Describe the concept of next-hop resolution.
- Scope of Answer: Discuss how routers determine the next device to send a packet to reach its destination.
- Key Points: Next-hop resolution, packet forwarding, routing.
- What is equal-cost multi-path (ECMP)?
- Scope of Answer: Explain the load balancing method using
- Key Points: equal cost path load balancing concept and example.
Jiwan is an accomplished IT Security Engineer and Trainer with 15 years of expertise, focusing on certifications such as CCIE and CEH. Beyond his technical skills, he is a dedicated vlogger, mindfulness guide, and active social worker. Jiwan advocates for life skills, independence, and critical thinking in his teachings, empowering IT professionals, learners, and spiritual seekers alike. His holistic approach integrates technical mastery with personal development, aiming to cultivate balanced lives where both professional success and personal fulfillment thrive.