I am encountering a puzzling challenge with OSPF adjacencies in a combined community setting and would enormously respect any insights or ideas.
Community Setup:
Units Concerned:
- A Cisco 2900 router.
- A bodily Layer 3 change operating FRR.
- A PC operating GNS3 with one digital Layer 3 change (additionally operating FRR).
Topology:
The digital Layer 3 change is linked to the bodily community through a hub.
Each the Cisco router and the bodily Layer 3 change are additionally linked to the identical hub.
The Difficulty:
- The Cisco 2900 router efficiently establishes OSPF adjacencies with each the bodily Layer 3 change and the digital Layer 3 change utilizing the default broadcast (multicast) hey packets.
- Nonetheless, the bodily and digital Layer 3 switches don’t kind an OSPF adjacency with one another—despite the fact that they will ping one another efficiently.
- Packet captures present that the bodily change will not be receiving the multicast OSPF hey packets (despatched to 224.0.0.5) from the digital change.
- After I reconfigure the digital change to make use of non-broadcast (unicast) hey packets, the OSPF adjacency is efficiently fashioned. Nonetheless, I choose to make use of the default broadcast configuration throughout all gadgets.
Further Notes:
I’ve verified that there aren’t any points with widespread OSPF parameters:
- Authentication: Not an element.
- Router Priorities: Correctly configured.
- MTU Settings: Constant throughout the gadgets.
The Cisco router forming adjacencies with each switches confirms that fundamental connectivity and multicast forwarding by the hub are functioning accurately.
My Query:
Has anybody skilled an analogous challenge or have any insights into why the bodily and digital Layer 3 switches fail to kind an OSPF adjacency utilizing multicast hey packets, regardless of all gadgets having the ability to talk and the Cisco router forming adjacencies with out points? I am notably involved in understanding any potential subtleties in how FRR handles multicast on totally different platforms or different configuration nuances that may trigger this conduct.
Thanks prematurely in your assist!