Whether Load Balancing & Failover works on multiple gateways on single NIC?

[shersinghrawat]

I have two NICs one LAN and other WAN. WAN interface is configured three internet gateways.

I like to ask whether load balancing and failover work the same way as it works with multiple WAN interfaces or do i need different interfaces for each internet gateways?

I use static ips for Desktops and pfsense DHCP for wireless devices with DHCP static mapping for each device. My aim is to  restrict internet bandwidth and apply web filtering for clients based on IPs. I configure squid and squidguard webfiltering and working fine but how to restrict internet bandwidth.

Pls refer to attached images.