Abstract: A host-to-ToR switch advertisement protocol can be used at a data center network edge to receive IP advertisements from hosts and convey ToR switch availability status (e.g., in service, intentionally out of service, or unintentionally out of service) back to hosts and vice versa. The host server computers can have the ability to advertise an arbitrary number of IPv4 or IPv6 prefixes to the network through the ToR switches. A single host server computer can leverage multiple instances across multiple ports to the same switch or different switches to implement load balancing (e.g., equal cost multipath (ECMP)) and fault tolerance. The host server computers benefit from an increased availability by receiving network traffic via multiple ToR switches, a single ToR switch with multiple links, or a combination of both.

Abstract: An extension is provided to a Link Aggregation Control Protocol (LACP) that can use the LACP protocol transport and provides Link Aggregation Group (LAG) management while also functioning as a full liveness detection protocol. Bi-directional link detection is supported and timers are configurable to any number. The extension can be backwards compatible with standard LACP and can use a subtype that is specified as unused. The extension can start up using standard LACP packet rates and include additional information in the unused subtype. If a LACP speaker does not support the extension, then the protocol conforms to standard LACP. A state machine of the extension is used if it detects conforming information from a peer speaker. The state machine can allow faster detection should a link error occur.