Step-by-step how to display or view routing table on Linux Fedora Core machine.

Using Linux 'netstat' command to display or view kernel IP routing table.



[root@linux hack]# netstat -r

Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

203.106.93.64 * 255.255.255.224 U 0 0 0 eth0

10.2.0.0 * 255.255.0.0 U 0 0 0 eth1

10.3.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.6.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.7.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.4.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.5.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.10.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.8.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

169.254.0.0 * 255.255.0.0 U 0 0 0 eth1

10.9.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

default 203.106.93.93 0.0.0.0 UG 0 0 0 eth0

[root@linux hack]# netstat -nr

Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

203.106.93.64 0.0.0.0 255.255.255.224 U 0 0 0 eth0

10.2.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1

10.3.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.6.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.7.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.4.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.5.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.10.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.8.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1

10.9.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

0.0.0.0 203.106.93.93 0.0.0.0 UG 0 0 0 eth0



Using Linux 'route' command to display kernel IP routing table.



[root@linux hack]# /sbin/route

Kernel IP routing table

Destination Gateway Genmask Flags Metric Ref Use Iface

203.106.93.64 * 255.255.255.224 U 0 0 0 eth0

10.2.0.0 * 255.255.0.0 U 0 0 0 eth1

10.3.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.6.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.7.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.4.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.5.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.10.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

10.8.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

169.254.0.0 * 255.255.0.0 U 0 0 0 eth1

10.9.0.0 10.2.0.2 255.255.0.0 UG 0 0 0 eth1

default 203.106.93.93 0.0.0.0 UG 0 0 0 eth0



Step-by-step how to add/change default route on Linux Fedora Core machine.



You can add default route on your Linux machine by using route command.



[root@linux hack]# route add default gw 10.10.0.1 eth0



Add or edit the default gateway on /etc/sysconfig/network file, to make sure your default is preserve after your system boot.



Configuration example on network file:



NETWORKING=yes

HOSTNAME=fedora.hacking.com

GATEWAY=203.106.93.93



Or you can place the (# route add default gw 10.10.0.1 eth0) command to the rc.local script file. This rc.local script file is located under /etc/rc.d/rc.local. This rc.local script file are design to run at the end of each boot time.