# OSPF Summary LSA Loop Prevention

DevFeed: [OSPF Summary LSA Loop Prevention](<https://devfeed.tech/articles/ospf-summary-lsa-loop-prevention-11170.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2025/04/ospf-summary-lsa-loop-prevention/>)

Published: 2025-04-30T06:17:00Z

Content type: tutorial

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [networking](<https://devfeed.tech/topics/networking.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>), [IP routing](<https://devfeed.tech/topics/ip-routing.md>), [Routing (disambiguation)](<https://devfeed.tech/topics/routing.md>)

Tags: [ip-routing](<https://devfeed.tech/tags/ip-routing.md>), [networking](<https://devfeed.tech/tags/networking.md>), [ospf](<https://devfeed.tech/tags/ospf.md>), [protocol](<https://devfeed.tech/tags/protocol.md>), [routing](<https://devfeed.tech/tags/routing.md>)

## AI overview

This article explains how OSPF prevents an ABR from advertising a Type-3 summary LSA generated from area 1 prefixes back into area 1. The route-selection process prefers intra-area paths over inter-area paths, so the ABR does not use the inter-area route for summary-LSA generation.

## Source excerpt

A networking-focused entity known only as humblegrumble sent me the following question after reading my When OSPF Becomes a Distance Vector Protocol article: How do A1 and A2 know not to advertise a Type-3 summary LSA generated from area 1 prefixes back into area 1? He's right. There is no "originating area" information in the type-3 LSA, so how does an ABR know not to reinsert the type-3 LSA generated by another ABR back into the area? TL&DR: The OSPF route selection process takes care of that. Read more ...