Navigation
Supported Platforms
Related Documentation
GRE Keepalive Time Overview
Generic routing encapsulation (GRE) tunnel interfaces do not have a built-in mechanism for detecting when a tunnel is down. You can enable keepalive messages to serve as the detection mechanism.
Keepalives can be configured on the physical or on the logical interface. If configured on the physical interface, keepalives are sent on all logical interfaces that are part of the physical interface. If configured on a individual logical interface, keepalives are only sent to that logical interface. In addition to configuring a keepalive, you must configure the hold time.
