Configuring a Cisco router

First of all telnet into the router: "telnet |router IP - usually 192.168.0.1 or 10.10.10.1|" then you will be prompted for username and password:

Username:

After you enter it and hit [enter] you will get:

Password:

After you enter that and hit [enter], you should get a prompt looking something like this:

Router>

Now, write down the "enable" command and hit [enter]. Notice that after you enter the password and hit the [enter], key the prompt will change to display the pound sign after the router name:

Router#

Now that you are in priviliged mode enter the following command:

"configure terminal"

This will let your router know that you wish to configure it. You should now see the following message and prompt:

Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#

Now comes the actual config line as follows:

ip nat inside source static tcp |Internal IP| |Port| interface |Name| |port|
or:
ip nat inside source static udp |Internal IP| |Port| interface |Name| |port|

where "Port" is your TCP port (mine is 4662, for example) and "Internal IP" is the ip for the machine that is actually running E-mule (Make a habit out of configuring the PC's IP manually and do not trust the DHCP to assign you the same IP every time) and "name" is the name of the dialer interface that is bound to your WAN physical interface (for example Mine is "dialer1" - that will usually be the case).

If, for some reason, this fails to work, try adding the word "extendable" to the end of the line, like so:

ip nat inside source static tcp |Internal IP| |Port| interface |Name| |port| extendable
or:
ip nat inside source static udp |Internal IP| |Port| interface |Name| |port| extendable

If you wish to undo the changes made you will need, as with most commands of the cisco routers, to enter the line again, this time with the word "no" at the beginning:

No ip nat inside source static tcp |Internal IP| |Port| interface |Name| |port| extendable
or:
No ip nat inside source static udp |Internal IP| |Port| interface |Name| |port| extendable

And now for a full demonstration:

ip nat inside source static tcp 10.10.10.157 4662 interface dialer1 4662
ip nat inside source static udp 10.10.10.157 4672 interface dialer1 4672
ip nat inside source static tcp 10.10.10.152 5662 interface dialer1 5662
ip nat inside source static udp 10.10.10.152 5672 interface dialer1 5672

The first line configures TCP for my PC. The second handles UDP. The two other lines forward the needed ports to my brother's PC (we both run E-mule with high ID and an open kad network).

Credits to SHETAH for this guide.