Routing

Hi.

I understand that the LS Request message is required for OSPF database synchronization during the creation of an OSPF adjacency between two routers. However, once both databases are synchronized and the adjacency is FULL, is there any scenario where an LS Request message can be seen over the FULL adjacency?

Thanks.

Hi 

The link state request message is sent just after the Database Description exchange. Once the requested link state are exchanged and the adjanceny is full then only link state update (LS update) and link state acknowledge (LS ack) is exchanged whenver there is change in the ospf domain. I dont think there is any scenario where LS request is seen after the adjacency is full.

Check out the RFC

https://www.freesoft.org/CIE/RFC/1583/106.htm

Hey djadhav,

Greetings, I hope you are doing great! as you mentioned LS Request message is required for OSPF database synchronization during the creation right before going to full, after the adjacency is full there is a lsa-refresh feature that keeps the database synchronize. 

The OSPF standard requires that every LSA be refreshed every 30 minutes. The Juniper Networks implementation refreshes LSAs every 50 minutes. By default, any LSA that is not refreshed expires after 60 minutes, hence if your concern if how the LSDB keeps synchronized that's how it works.

If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/

Regards,

Lil Dexx
JNCIE-ENT#863, 3X JNCIP-[SP-ENT-DC], 4X JNCIA [cloud-DevOps-Junos-Design], Champions Ingenius, SSYB