[dev] OSPF Adjacency Behavior with BFD Shutdown State

[Acee Lindem]

Hi Jagadeesh, 

There is a standard for OSPF BFD strict-mode - https://datatracker.ietf.org/doc/rfc9355/

However, it is not supported by FRR yet .

Thanks,
Acee

> On Jul 23, 2025, at 7:06 PM, Jagadeesh Banavara via dev <dev at lists.frrouting.org> wrote:
> 
> 
> From: Jagadeesh Banavara <jbanavara at infoblox.com>
> Subject: OSPF Adjacency Behavior with BFD Shutdown State
> Date: July 23, 2025 at 7:06:38 PM EDT
> To: "dev at lists.frrouting.org" <dev at lists.frrouting.org>
> 
> 
> 
> Hi,
> 
> I’ve observed a behavior and wanted to check if there’s a recommended approach or configuration to address it.
> 
> When a BFD profile transitions to the shutdown state (admin down), it correctly brings down the OSPF adjacency. However, after a few seconds, the adjacency is re-established—even though the BFD session remains down. In contrast, BGP has a ‘strict' mode that prevents session establishment until the BFD session is up.
> 
> Is there a similar mechanism or means available in FRR to keep OSPF down as long as the associated BFD session is in the down state?
> 
> Any guidance or suggestions would be greatly appreciated.
> 
> Thanks,
> Jagadeesh
> 
> 
> 
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