... This topic is a quick help to enable IP routing as fast as possible on various systems & platforms without needing to another program to be run or so on.
IP routing also known as IP Forwarding, needs when the system has more than one NIC or network interface or network connection (such as LAN connection, PPP,...) & you want to route between them to provide for example a gateway, NAT, firewall,... .
1. Cisco Routers/Access Servers :
IP routing is automatically enabled in the Cisco IOS software for routers. To reenable IP routing if it has been disabled on "Global Configuration" type: IP Routing
2. All Microsoft Windows Platforms :
Run "regedit" program and go to the following path :
then change the REG_DWORD value (or add new if no exists) from "0" to "1" and reboot the system.
3. Linux :
Add the following command to "/etc/rc.local" then reboot :
echo 1 > /proc/sys/net/ipv4/ip_forward
Or ff you're running Debian linux, you can just put :
4. BSD Unix Family :
On "/etc/rc.conf" change the following variable to "YES" then reboot :
For on demand routing enable/disable using sysctl for "net.inet.ip.forwarding" either to "1" or "0".
5. Sun Solaris :
Run this command at prompt:
ndd -set /dev/tcp ip_forwarding 1
But this only lasts until reboot.
To make this happen every boot, put it in a shellscript in /etc/rc2.d -- it must run after S69inet, so call it something like S70ipforwarding
Under certain circumstances (such as more than one interface and no default router), ip_forwarding is automatically turned on, but the precise circumstances vary with Solaris releases, and never suit everyone.
6. Novell Netware :
Edit autoexec.ncf, look for the "load tcpip" line.
Change it to read "load tcpip forward=yes".