Not using failover means: use main routing table.
If main routing table has 2 default routes with equal metric (equi-distant), packets will still be sent on both links in 50/50 ratio.
To force 1 link for a specific host, add a routing table and force the host to use it.:
set protocols static table 2 route 0.0.0.0/0 next-hop 192.0.113.1 set firewall modify SOURCE_ROUTE rule 10 description Force_WAN2 set firewall modify SOURCE_ROUTE rule 10 source address 10.0.0.123/32 set firewall modify SOURCE_ROUTE rule 10 modify table 2
