The netstat -nr command will provide the contents of the touting table. Networks with a gateway of 0.0.0.0 are usually directly connected to the interface. No gateway is needed to reach your own directly connected interface, so a gateway address of 0.0.0.0 seems appropriate. The route with a destination address of 0.0.0.0 is your default gateway.
# netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
172.19.12.0 0.0.0.0 255.255.254.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 172.19.12.1 0.0.0.0 UG 0 0 0 eth0
Change Your Default Gateway
you’ll need to update your /etc/sysconfig/network file to reflect the change. This file is used to configure your default gateway each time Linux boots.