Interfaces

If an interface is isolating downstream failures, then the interface failure can suppress the downstream failures.

Connected interfaces

An interface failure A can suppress a subsequent interface failure B if the two interfaces are directly connected. The interface whose suppression rule fires first, suppresses the other interface. Suppression of an interface failure B by an earlier failure A on a connected interface can only occur if the following conditions hold:
  • Interface failure B is not already being contained-suppressed.
  • Interface failure A is not already being isolated-suppressed.
  • Interface failure A is not already being connected-suppressed.
  • The chassis that contains interface A is not being isolated-suppressed.
  • The chassis that contains interface A is not being connected-suppressed.

Furthermore, if interface failure B happened to be connect-suppressing interface failure A first and then later on the topology state changed so that instead A now isolated B, then the connected suppression of A by B would be removed and A would then isolate-suppress B.

Physical and logical interfaces

A physical interface can contain multiple logical interfaces. A failure on a physical interface can suppress failures on its related logical interfaces. The physical interface can suppress its related logical interface even if there is connectivity between the logical interface and an external neighbor. Even events on a suppressed physical interface can contain-suppress events on its associated logical interfaces.