ip route flush cache
ip route flush table 99
ip route add default table 99 equalize nexthop via 192.168.1.243 nexthop via 192.168.1.242


ip route show cache example:

...
79.0.112.165 from 192.168.1.222 via 192.168.1.242 dev eth0
    cache  mtu 1500 advmss 1460 hoplimit 64
79.0.112.165 from 192.168.1.222 via 192.168.1.243 dev eth0
    cache  mtu 1500 advmss 1460 hoplimit 64
83.14.44.162 from 192.168.1.222 via 192.168.1.242 dev eth0
    cache  mtu 1500 advmss 1460 hoplimit 64
83.14.44.162 from 192.168.1.222 via 192.168.1.243 dev eth0
...