How can I do a simulation of two WANs with different GWs if I have a single ISP in order to be able to practice load balancing?
Thank you.

Use Virtual Machine software (I use VirtualBox) to setup 2 Virtual CHR’s. You need 2 virtual ethernet interfaces for each. They need minimal setup:
##Gateway1
/ip address
add address=192.168.100.1/24 interface=ether2 network=192.168.100.0
/ip dhcp-client
add disabled=no interface=ether1
/ip firewall nat
add action=masquerade chain=srcnat out-interface=ether1
##Gateway2
/ip address
add address=192.168.200.1/24 interface=ether2 network=192.168.200.0
/ip dhcp-client
add disabled=no interface=ether1
/ip firewall nat
add action=masquerade chain=srcnat out-interface=ether1
And now on your Real Router add:
/ip address
add address=192.168.100.2/24 interface=bridge1 network=192.168.100.0
add address=192.168.200.2/24 interface=bridge1 network=192.168.200.0
Now you can use 192.168.100.1 & 192.168.200.1 as your gateways in the tutorials. Example:
/ip route
add check-gateway=ping distance=1 gateway=192.168.100.1 routing-mark=GW1
add check-gateway=ping distance=1 gateway=192.168.200.1 routing-mark=GW2
If you have 2 different gateways is one situation, if you have only 1 gateway you need L2 loadbalancing with is via portchannel
If all you want to do is simulate and view the traffic going out two different interfaces, you can probably use the
IP%interface
notation for the gateway values in the routing rules. So if your ISP LAN gateway is 192.168.0.1, and your WAN1 interface name is “ether1”, and your WAN2 interface name is “ether2” use
192.168.0.1%ether1 for the gateway value in your routing rule for WAN1, with the corresponding routing mark and
192.168.0.1%ether2 for the gateway value in your routing rule for WAN2, with the corresponding routing mark