Turn on IP forwarding in Linux IP.
To turn forwarding on temporarily, use the following command as root: (this will be disabled after a reboot)
echo "1" > /proc/sys/net/ipv4/ip_forward
Or to make it permanent add the following to
net.ipv4.ip_forward = 1
In older versions of Redhat / CentOS you can edit
/etc/sysconfig/network and enable it there:
#CRITICAL: Enable IP forwarding since it is disabled by default since # # Redhat Users: you may try changing the options in # /etc/sysconfig/network from: # # FORWARD_IPV4=false # to FORWARD_IPV4=true #
You can also add
echo "1" > /proc/sys/net/ipv4/ip_forward to
/etc/rc.local although the above methods are preferred.