Hello everyone,
I have a problem with my OSPF configuration. I am attaching a diagram below to better understand our network.
We have three datacenters connected together by dark fiber.
We have created a loop, DC 1 is connected to DC 2, DC 2 to DC 3 and finally DC 3 to DC 1.
We have servers on DC 1, DC 2 and DC 3.
The servers on DC 1 are backed up on DC 2, those on DC 2 are backed up on DC 3 and those on DC 3 are backed up on DC 1. We use OSPF to announce networks to other sites.
On the diagram, in green, I noted the interconnection networks between the DCs. All ports connected to the dark fiber are in access mode placed in the dedicated vlan.
In the white square placed on the switches, I noted the networks announced by the OSPF interfaces.
My problem is that RSTP blocks a port on the DC 3 switch to avoid the loop. The dark fiber between DC 2 and DC 3 is useless.
The backup traffic of the DC 2 servers (the red line) goes through DC 1 before going back down to DC 3.
In my mind, OSPF optimizes traffic by taking the shortest path between the source route and the destination route, the whole point being to recalculate the routing table when a link goes down.
When I look at blogs on OSPF, I find diagrams identical to mine and none of them talk about the problems of layer 2 loops.
My problem is also that this design implemented for one region, we want to implement it also on other regions where we have several data centers.
Has anyone in the community already set up this type of diagram or am I wrong with this design?
Thanks in advance to everyone, if my explanation is not detailed enough, I will answer all the additional questions.
Best regards,
Gael
