OSPF


Incremental SPF is an improvement in the efficiency of [OSPF](/ospf) such that only the portions of the Shortest Path Tree (SPT) that have changed are included in the execution of the algorithm.  Under normal circumstances, when an OSPF router receives an LSA of any type that is new, it will run the SPF algorithm in full.

Whether a full SPF or an incremental SPF is run It does not depend on whether a single LSA or the whole LSDB is exchanged.  It has to do with the the way in which the received updates are processed.

For further information about the different LSA types, take a look at:

[OSPF LSA Types](/ospf-lsa-types)

## Links

https://networklessons.com/cisco/ccie-routing-switching-written/ospf-incremental-spf

https://networklessons.com/ospf/ospf-lsa-types-explained

https://networklessons.com/ospf/ospf-lsas-and-lsdb-flooding-tutorial

OSPF Incremental SPF and receipt of LSAs

OSPF - LSA Max Age

OSPF - LSA Refresh Time

OSPF - LSA checksum

OSPF - Link ID and ADV Router in the OSPF database

OSPF - Link ID in the OSPF database

OSPF - Link State Updates (LSUs)

OSPF - MPLS SuperBackbone

OSPF - NBMA neighbors listen on 224.0.0.5

OSPF - NSSA P-bit

OSPF - NSSA no automatic default route

OSPF - Neighbor states

OSPF - Neighbor vs Adjacency

OSPF - OSPFv3 authentication

OSPF - Propagation of routes between areas

OSPF - Stub areas and allowed LSAs

OSPF - Stuck in ATTEMPT neighbor state

OSPF - Stuck in ExStart or Exchange states

OSPF - Type 5 LSA filtering on an ASBR

OSPF - Type1 LSA

OSPF - Update pacing timers

OSPF - capablity vrf-lite

OSPF - control plane vs data plane loops

OSPF - default-information originate always command

OSPF - distance command

OSPF - distribute-list filtering

OSPF - manual neighbor configuration

OSPF - network type mismatch

OSPF - non-zero Forwarding Address example

OSPF - point-to-multipoint network type

OSPF - route summarization

OSPF - summary-address nssa-only on an ABR

OSPF - what triggers a DR-BDR election

OSPF ABR Type 3 LSA filtering using access lists

OSPF ABR and Loop Prevention

OSPF Authentication for v2 and v3

OSPF BDR to DR Transition Time

OSPF DR BDR election and neighbor adjacencies

OSPF DR BDR election criteria

OSPF DR BDR election process

OSPF Database Exchange Process Master Slave Election

OSPF Design - When to create new instance

OSPF Determining which LSA is newer

OSPF Discontiguous Area 0

OSPF Do Not Age (DNA) Flag

OSPF E1 E2 N1 N2 routes

OSPF Forwarding Address

OSPF Hello packets unicast and multicast

OSPF IP Unnumbered

OSPF IS-IS comparison

OSPF LSA Persistence with DNA flag

OSPF LSA Recursion

OSPF LSA Sequence Numbers

OSPF LSA Types

OSPF NSSA ABR advertises default route

OSPF Not So Stubby Area NSSA

OSPF Packet Types and Their Transmission Methods

OSPF Path selection

OSPF Prefix Suppression Considerations

OSPF Route Filtering

OSPF Routing Bit

OSPF SPF Scheduling and throttling timers

OSPF Summarization Restrictions Within an Area

OSPF TTL Security Check

OSPF Troubleshooting

OSPF Type 3 LSA

OSPF Type 4 LSA

OSPF Type 5 LSA

OSPF Type 7 LSA

OSPF Understanding LSA Aging and Refreshing

OSPF Why it is not suitable for use on the Internet

OSPF advertising loopback network

OSPF area inactive

OSPF area notation

OSPF area type mismatch

OSPF backbone area 0

OSPF default metric values

OSPF design - when to create a new area

OSPF does not redistribute default route

OSPF downheap LSA

OSPF duplicate router IDs

OSPF extent of reconvergence process

OSPF immediate hello packet

OSPF in a GRE multipoint environment

OSPF loop prevention

OSPF message options field

OSPF metric sum of outgoing interface costs

OSPF modifying the router ID

OSPF network command

OSPF network types

OSPF non directly connected neighbor adjacencies

OSPF packet types

OSPF point to point network type for Ethernet

OSPF requirements for forming adjacency

OSPF router ID in an IPv6 environment

OSPF router ID

OSPF sham-link cost

OSPF sham-link

OSPF virtual link and ABRs

OSPF where do you configure a virtual link

OSPF Incremental SPF and receipt of LSAs

Links

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