Networking Interview Question for routing protocol
OSPF
Q. How many types of area exist in OSPF and types of LSA are allowed ?
Q. Different OSPF packet types ?
Q. If you see how as DRother under show ip ospf neigbor . Whats wrong with the output ?
Q. How OSPF acts as distance vector and link state protocol and when ?. Explain how.
Q. How OSPF avoid loops in the network. Explain how.
Q. Why do we need concept of area and why backbone area is required ?
Q. How OSPF support MPLS TE tunnel ? Explain.
Q. How many routers are recommended in OSPF area and what the limit of routers in OSPF domain?
Q. What is iSPF, BFD, Graceful restarts and BFD in OSPF.
Q. What is the SPF algorithm and how does it work .
Q. What trigger the OSPF SPF in the network and how to avoid and reduce the SPF calculations ?
Q. When OSPF routers use multicast address and unicast address ?
Q. OSPF is layer 2 or layer 3 protocol ?
Q. Best practices to implement OSPF in Data center/Enterprise/WAN ?
Q. What is an OSPF area?
Q. What are the differences between LSA structures of area ?
Q. Troubleshoot the exhange/exstart state with OSPF ?
Q. Can a non-backbone area be connected to another non-backbone area and not to backbone?
Q. We want to redistribute routes into a non-backbone Type-5. What type of area would that be?
Q. What need to be similar in the hello packet in-order to form OSPF adjacency?
Q. In what case OSPF adjacency get stuck in Attempt state??
Q. In what case OSPF adjacency get stuck in Extract state??
Q. Does OSPF form adjacency with the neighbor that are on the different subnet??
Q. OSPF load balancing scenario?
Q. How OSPF Forwarding works and why do we need ?
Q. Options to connect non backbone area to backbone area over another non-backbone area ?
Q. When link-state-request and link-state-update in use on OSPF ?
Q. In scenario of 4 ABR in the network, which ABR will advertise the network ?
Q. With which network type will OSPF establish router adjacencies but not perform the DR/BDR election process?
Q. What is the administrative distance of OSPF?
Q. How OSPF virtual link and Sham link work and where it used in the network ?
Q. What are the different types of router link types ?
Q. What are the different types of bits used in OSPF packet types including V B E ?
EIGRP
Q. EIGRP is distance vector or link state ? Q. How EIGRP avoid loops in the network ? Q. What is feasible condition in EIGRP ? Q . What is SIA in EIGRP and how to solve it ? Q. How reliable mechanism work in EIGRP ? Q. Where EIGRP use multicast and unicast packet for the neighbor relationship. ?
Q. Best practices to implement in enterprise and Data center.
ISIS
Q. How ISIS scales better then OSPF ?
Q. What is ATT bit and route -leaking and why it is required ?
Q. What is level 1 and level2 in ISIS ?
Q. What is pseudonode/DIS and how it communicates ?
Q. ISIS is distance vector or link state protocol ?
Q. How ISIS prevent loop in the network ?
Q. What is the difference between narrow and wide metrics ?
Q. Describe the ISIS route selection process ?
