# Troubleshooting OSPF Neighbor Adjacency

**URL:** https://forum.networklessons.com/t/troubleshooting-ospf-neighbor-adjacency/1190
**Category:** Lessons Discussion
**Created:** [December 27, 2016, 11:40pm UTC](https://forum.networklessons.com/t/troubleshooting-ospf-neighbor-adjacency/1190 "2016-12-27T23:40:33Z")
**Posts on this page:** 1
**Showing post:** 69

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### Author: ![lagapidis](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/lagapidis/32/4949_2.png) [@lagapidis](https://forum.networklessons.com/u/lagapidis)
#### Post date: [December 16, 2025, 6:35am UTC](https://forum.networklessons.com/t/troubleshooting-ospf-neighbor-adjacency/1190/69 "2025-12-16T06:35:02Z")

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Hello David

Take a look at my response here, it should clear up the issue:

> [@OSPF Packets and Neighbor Discovery](https://forum.networklessons.com/t/ospf-packets-and-neighbor-discovery/916/126):
>
> Hello David You’re right that the RID is included in the hello messages. Even so, OSPF does not check that the RIDs are unique during that exchange (zany_face wierd right?). The protocol itself, as described in the RFC has no mandate for OSPF to check RIDs during that exchange. Other things are checked during the hello exchange including area IDs, network mask of interfaces (on broadcast/NBMA networks), timers, authentication, and stub area flags. But not the Router ID! The duplicate RI…

I hope this has been helpful!

Laz

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