Final answer:
The open standard variant of HSRP is VRRP, which provides failover capability and can be implemented on various vendors' hardware, unlike the Cisco proprietary HSRP and GLBP.
Step-by-step explanation:
The open standard variant of HSRP (Hot Standby Router Protocol) is VRRP (Virtual Router Redundancy Protocol). VRRP is a redundancy protocol that provides the automatic assignment of available IP routers to participating hosts. This ensures the continuity of network service by providing failover capability.
HSRP is a Cisco proprietary redundancy protocol, which means it is designed to work on Cisco devices. On the other hand, VRRP is an open standard which means it can be implemented on different vendors’ hardware that supports the protocol. While GLBP (Gateway Load Balancing Protocol) also provides redundancy, it is Cisco proprietary and not an open standard. OSPF (Open Shortest Path First) and RIP (Routing Information Protocol) are routing protocols and not relevant to the context of redundancy like HSRP or VRRP.