EAPS Shared Port Configuration Rules

The following rules apply to EAPS (Extreme Automatic Protection Switching) shared port configurations:

  • Each common link in the EAPS network must have a unique link ID, which is configured at the shared port at each end of the link.
  • The shared port mode configured on each side of a common link must be different from the other; one must be a controller and one must be a partner.
  • The controller and partner shared ports on either side of a common link must have the same
  • link ID. The common link is established only when the shared ports at each end of the common link have the same link ID.
  • There can be up to two shared ports per switch.
  • There cannot be more than one controller on a switch.

    Valid combinations on any one switch are:

    • 1 controller
    • 1 partner
    • 1 controller and 1 partner
    • 2 partners
  • A shared port cannot be configured on an EAPS master‘s secondary port.



    When a common link fails, one of the segment ports becomes the active-open port, and all other segment ports are blocked to prevent a loop for the protected VLANs. For some topologies, you can improve network performance during a common link failure by selecting the port numbers to which segments connect. For information on how the active-open port is selected, see Common Link Fault Detection and Response.