18 - OSPF - CBT CCNP VID 9 - basic

Question 1

Routing protocol all have 3 tables, which are ?

Answer 1

• neighbour table
• topology table
• routing table

Question 2

EIGRP & OSPF Topology tables differ how ?

Answer 2

EIGRP Topology
- knows only the routes connected to it, 1st route & 2nd best route

Ospf topology

• know the topology of the whole network in its area
• All routes are known (only best in Routing table)

Ospf updates topology

• triggered updates (announce to whole network)
• send periodic updates (link state refresh, LSF) once in every 30sec

Question 3

What is the backbone area ?

Answer 3

Area Zero - 0

All area must connect to area zero

Question 4

what is ABR ?

what does it do ?

Answer 4

ABR= area boarder router

• restricts triggered updates to its own area
• this prevent topology calculation on every router in every areas
• this requires ip hierarchy (sometimes location too)

Question 5

What is ASBR and what does it do ?

Answer 5

ASBR= autonomous system boundary router

- Outside of OSPF system, e.g EIGRP,BGP etc

Question 6

what Router names can you do Summarisation on ?

Answer 6

• only in abr & asbr