I am currently rate limiting by IP but the issue is I have dual active WAN connections. The default gateways are distributed with OSPF and ECMP. This works great except on how to configure the rate limiting. Below is the config that was sent to us to use but how to we modify it to accept both outbound interfaces.

/ip firewall mangle
add action=mark-connection chain=forward dst-address-list=100M new-connection-mark=100M_traffic_down out-interface=WAN1 passthrough=yes
add action=mark-connection chain=forward src-address-list=100M new-connection-mark=100M_traffic_up in-interface=WAN1 passthrough=yes
add action=mark-packet connection-mark=100M_traffic_down chain=forward new-packet-mark=100M_traffic_down out-interface=WAN1 passthrough=yes
add action=mark-packet connection-mark=100M_traffic_up chain=forward new-packet-mark=100M_traffic_up in-interface=WAN1 passthrough=yes
/queue type
add kind=pcq name=100M_download pcq-classifier=dst-address pcq-dst-address6-mask=64 pcq-rate=100M pcq-src-address6-mask=64 pcq-total-limit=250000
add kind=pcq name=100M_upload pcq-classifier=src-address pcq-dst-address6-mask=64 pcq-rate=100M pcq-src-address6-mask=64 pcq-total-limit=250000
/queue tree
add name=100M_download packet-mark=100M_traffic_down parent=WAN1 queue=100M_download
add name=100M_upload packet-mark=100M_traffic_up parent=ether1 queue=100M_upload