I'm currently designing a spine leaf network, 2 Spine switches and 4 leaf switches. btw this in packet tracer.


So in order its Spine1# and Spine2#, then Leaf1#, Leaf2#, Leaf3#, Leaf4#, and addresses are through to .11.

What I've done is created VLAN 1 on all the devices and then assigned then the IP addresses I stated above in that order.

Next, I configured on Spine1# OSPF (I assume that I've configured it)

interface Vlan1
 ip address
router ospf 1
 network area 1
ip classless
ip flow-export version 9

But when i try to see ospf neighbors from the second spine all i get is

Spine2#sh ip os ne
Spine2#sh ip os neighbor 


So I just get a blank line.

Any tips on how I should go about configuring OSPF as I'm sure I'm definitely doing it wrong.

  • 1
    Need to see ospf and interface configurations on both spines and at least one leaf. Feb 16, 2020 at 17:15
  • I would suggest you consider moving to a topology that's a series of point-to-point interfaces rather than a big shared subnet. This is much closer to actual best practice and has a bunch of advantages in terms of traceability, faster convergence and eliminating a lot of potential problems around DR/BDR election. This final point is also worth considering in the above design as you've got potential for some odd consequences in that the spines can't speak directly for said election (again - this issue disappears when going to p-t-p, as well as simplifying adding a 3rd or 4th spine device).
    – rnxrx
    Feb 17, 2020 at 4:12

1 Answer 1


Configuring a single router with OSPF does nothing but waste CPU cycles on a router. Routing protocols do not route, they exchange routing information with other routers running the same routing protocol.

Also, if all you have is a single network, then routing is completely unnecessary because routers route packets between networks, not from a network back to the same network. Bridges (switches are bridges) will switch frames between hosts on the same network (no routing protocol needed).

If you want to share routes between the two routers (spine switches), you must first enable routing on those switches with the ip routing command. Then you can run OSPF on both routers. With OSPF, they must be in the same area in order to become neighbors.

Because you have only one network, the OSPF neighbors will not share any routes; each router already knows how to reach that network because it is directly connected to both routers.

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