EAP port roles on transit switch

  • 8 February 2017
  • 5 replies

Can anyone explain the significance of primary and secondary ports for a transit switch within an EAPS ring? I understand that for a master switch this identifies which port would be blocked for the associated VLANs under normal operation, but what does it mean for a transit switch?

5 replies

Userlevel 5
Hi Paul,

Basically, for transit nodes it does not make any difference which port is primary or secondary. It is however good practice to have all ports point in the same direction.

If you ever need to change the role of the node or when there is a need for trouble shooting.
Userlevel 4
Hi Paul,
As Ron mentioned earlier, there's no difference between two types of ports on transit node.
Although primary and secondary ports are configured on transit nodes, both port types operate identically as long as the transit node remains a transit node.
If the transit node is reconfigured as a master node, the configured states of the primary and secondary ports apply.
But in EAPS multiple ring topology, a shared port cannot be configured on an EAPS master’s secondary port.
So if you plan to change role of the node, you may change type of ports based on your implementation.

Could you explain what you mean by a 'shared port'?
Userlevel 4
Actually, you don't need to consider it when there's only a single EAPS ring topology.
But it is used to prevent a "super loop" in EAPS multiple ring.

I think it's better for you to read the "EAPS Multiple Ring Topology" in EXOS user guide since it's the most complicated part of the EAPS.