Port forwarding is a term used to described forwarding rules that you setup on a firewall/router for specific type of IP traffic. As an example you may have an email server behind your firewall that your employees want to remotely access. In this case, you can create a port forwarding rule on your firewall that NATs (Network Address Translation) and port forwards the inbound traffic directed to your static public IP on your firewall onto the local IP address of your email server. The response to that inbound traffic will go through the reverse process whereby the firewall will translate the local LAN IP of the server (the source IP of the packets) with the static IP of the firewall and ship packets out the door.
As multi WAN routers become more common place within the enterprise networks, as an IT manager in most cases you a choice: you can keep your existing legacy firewall in place, or you can replace your existing firewall with the new multi WAN router.
The former is usually the quickest way to install the new hardware as long as your multi WAN hardware supports “pass-through” installation option. In this setup, the new router goes inline between the existing firewall and the existing primary modem. The advantage of this setup is that you don’t need to modify any of our port forwarding rules on your existing firewall, as a matter of fact, there is no change required in your setup as the new multi WAN router will be transparently installed, i.e. practically speaking will be invisible to the modem as well as the legacy firewall. This let’s you keep all the configuration intact, including the port forwarding rules.
Of course, you can replace your existing firewall with the built-in firewall capabilities of your multi WAN router if it supports those features. In that case, you will need re-configure the port forwarding rules, as well as any other firewall rules onto the new appliance.
Either option is viable, however, the pass-through installation where you can keep all firewall and port-forwarding rules intact let’s you complete multi WAN installation within minutes and therefore has the simplicity and transparency you may prefer.
Cahit Akin, CEO, Mushroom Networks, Inc.
Mushroom Networks is the provider of SD-WAN (Software Defined WAN) and NFV solutions capable of Broadband Bonding that enables self-healing WAN networks that route around network problems such as latency, jitter and packet loss.