FHRP Load Balancing Behavior
First hop redundancy protocols (FHRP Protocols) implement load balancing in different ways. The following list shows a summary of load balancing features for these protocols:
- HSRP on Cisco IOS devices does not perform load balancing. Traffic is always forwarded to the active router.
- HSRP on Cisco Nexus devices that are paired using vPC performs load balancing across both devices, even if a device is considered standby.
- VRRP can be configured to load balance manually, by creating two or more group numbers. Each router is assigned a different group number with a different virtual IP address. Hosts within the VLAN can be configured with a different default gateway, so that half of the hosts use one gateway, while the other half uses the other. If a gateway fails, all hosts will switch over to the active device. In this sense, load balancing is achieved "manually".
- GLBP can be used to perform load balancing automatically between redundant gateways.
Links: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_2/nx-os/unicast/configuration/guide/l3_cli_nxos/l3_hsrp.html#wp1232323 https://networklessons.com/cisco/ccie-routing-switching/vrrp-virtual-router-redundancy-protocol https://networklessons.com/cisco/ccie-routing-switching/glbp-gateway-load-balancing-protocol