Advanced Routing with iproute2
ip rule show
0: from all lookup local
32762: from 192.168.1.51 iif tuntest lookup rule_244
32763: from 172.31.23.244 iif tuntest lookup rule_244
32764: from 172.31.23.244 lookup 1
32765: from 172.31.23.244/24 lookup 1
32766: from all lookup main
32767: from all lookup default
delete a rule
ip rule del 172.31.23.244