IP forwarding also known as Internet routing is a process used to determine which path a packet or datagram can be sent. The process uses routing information to make decisions and is designed to send a packet over multiple networks.
Defaultly any UNIX/Linux distributions will have IP Forwarding is disabled. As most of the peoples will not need IP Forwarding, but if we are setting up a Linux router/gateway, when you want your system to act as VPN server, and for sharing the internet connection. See the below steps for enable or disable IP forwarding in linux.
Step1: Check the IP forwarding is enable or disable
In this step we have to check the IP forwarding using sysctl command
[root@bsrtech ~]# sysctl net.ipv4.ip_forward
Sample Output:
net.ipv4.ip_forward = 0
Step2: To Enable IP Forwarding Temporarily
To enable IP Forwarding temporarily,you can use any of the following commands
[root@bsrtech ~]# echo 1 > /proc/sys/net/ipv4/ip_forward
(or)
[root@bsrtech ~]# sysctl -w net.ipv4.ip_forward=1
To check the IP Forwarding is enabled or not , execute the following command
[root@bsrtech ~]# sysctl net.ipv4.ip_forward
Step3: To Enable IP Forwarding Permanently
To enable IP forwarding permanently, you can change value in configuration file /etc/sysctl.conf
[root@bsrtech ~]# vim /etc/sysctl.conf
you can find the line "net.ipv4.ip_forward" and Set net.ipv4.ip_forward to 1
net.ipv4.ip_forward = 0
to
net.ipv4.ip_forward = 1
:wq (Save and close the file)
Step4: Reload the changes
To load the settings that we made to /etc/sysctl.conf file, run the following command
[root@bsrtech ~]# sysctl -p
Sample Output:
Step5: To Disable IP forwarding Permanently
you can find the line in /etc/sysctl.conf "net.ipv4.ip_forward" and Set net.ipv4.ip_forward to 0
net.ipv4.ip_forward = 1
to
net.ipv4.ip_forward = 0
:wq (save and close the file)
Reload the changes using sysctl command
[root@bsrtech ~]# sysctl -p
Sample Output:
0 comments:
Post a Comment