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Turn an Old PC into a LAN Server with RouterOS, Part 2

Article Description

Want an enterprise router for your network at a fraction of the cost of a Cisco router? You can connect your offices together, remotely access files, run enterprise Wi-Fi encryption, and more. Eric Geier, author of Wi-Fi Hotspots: Setting Up Public Wireless Internet Access, concludes his two-part tutorial on getting a RouterOS machine up and running on a spare PC.
Enable NAT to Share the Internet

Enable NAT to Share the Internet

The final step of creating a basic Internet-sharing router is to enable Network Address Translation (NAT). This process makes sharing an Internet connection possible.

Remember, each computer or device must have an IP address to communicate on a network or on the Internet. But you only get one IP address for your Internet connection. Thus NAT is needed to "trick" the Internet into thinking communication from any computer or device on your local network is coming from your router.

In other words, it makes your router the single contact point or relay between your network and the Internet.

Here's how to enable NAT on RouterOS, using WinBox:

  1. Click IP > Firewall and select the NAT tab.
  2. Click the Plus button to add a new firewall rule.
  3. For the Chain, select "srcnat".
  4. For the Src Address, input the IP range of your local network. For example, if the router IP is, you'd type
  5. For the Out Interface, select the name for the interface that's connected to the Internet.
  6. Click the Action tab.
  7. For the Action, choose "Masquerade".
  8. Click OK to save the changes.
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