OSPF backbone area 0
OSPF requires that a backbone area exist for all OSPF topologies. The backbone area is always defined as Area 0. All areas that are not Area 0 are considered non-backbone areas. All non-backbone areas must have an ABR that is also connected to Area 0. To find out why, take a look at OSPF why is a backbone area 0 necessary.
Area 0 must exist on at least one interface of an ABR router.
Links
https://networklessons.com/ospf/introduction-to-ospf https://networklessons.com/ospf/basic-ospf-configuration https://networklessons.com/ospf/ospf-multi-area-configuration
Links to this page:
- DMVPN - OSPF and multiple areas
- MPLS - L3VPN BGP OSPF Redistribution
- OSPF - ABR has at least one interface in Area 0
- OSPF - Area Border Router (ABR)
- OSPF - Autonomous System Boundary Router (ASBR)
- OSPF - ECMP to destination in Area 0
- OSPF - Enabling authentication
- OSPF - Identifying the router type
- OSPF - Link State Updates (LSUs)
- OSPF - Propagation of routes between areas
- OSPF - Type 5 LSA filtering on an ASBR
- OSPF ABR and Loop Prevention
- OSPF Design - When to create new instance
- OSPF NSSAs, Totally NSSAs and Default Routes
- OSPF Route Preference Intra-Area vs Inter-Area
- OSPF Type 3 LSA
- OSPF design - when to create a new area
- OSPF requirements for forming adjacency
- OSPF why is a backbone area 0 necessary
- OSPF within what area is an OSPF router considered to be
- OSPF