With two distribution multilayer switches as default gateways, which two technologies enable every VLAN host to use both gateways?

GLBP (Gateway Load Balancing Protocol) allows multiple routers to share a single virtual IP address and MAC address, but it can assign different virtual MAC addresses to different hosts, enabling true load balancing across multiple gateways. VSS (Virtual Switching System) combines two physical Cisco Catalyst switches into a single logical switch, presenting a unified control plane and data plane. This allows both switches to act as a single default gateway for all VLANs, effectively utilizing both forwarding paths. HSRP (Hot Standby Router Protocol) and VRRP (Virtual Router Redundancy Protocol) operate in an active/standby fashion, meaning only one gateway is actively forwarding traffic at a time, so they don't allow every VLAN host to use both gateways simultaneously. MHSRP (Multi-Group HSRP) allows for multiple HSRP groups but still operates in active/standby within each group, not enabling simultaneous use of both gateways for a single VLAN.