Title:
MultiWAN with RouterOS
Welcome:
This article aims to bring clarity to the daunting and confusing task of routing multiple WAN and ISP provider connections in and out of your network. We will be using RouterOS version 7 firmware to accomplish these techniques. Examples will include Static IP wan connections, DHCP assignments, PPPoE encapsulations, and using LTE as a backup or main internet connection. Each style has its own unique requirements to get the most out of the WAN availability. What happens when one goes down? Do you want to dedicate one ISP to a certain type of traffic? How does incoming traffic reach internal targets? These solutions and more will be discussed.
MultiWAN is not SD-WAN:
Utilizing more than one internet provider is a way to bring more capacity and uptime to your network. If you have latency sensitive traffic, it can be helpful to put it on another WAN connection. However, multiple wan connections by themselves don’t necessarily create a seamless experience for end applications because of the way current TCP protocols are designed. An ISP failover may result in temporary application disruption.
Advanced applications can cope if they are programmed a certain way but streaming style applications are very suspect of background changes. There is a way, using a layer of external servers and routers, to achieve that high level of ISP float technique, where the applications are not aware of what is happening below. Illustrating this is not the purpose of this document which instead focuses on a more rudimentary way to manage multiple internet providers given you only have one router to manage.
Why MultiWAN?
This sounds like a trick question. If a single provider had amazing latency, enormous bandwidth, and never experienced any downtime, why indeed would there be the need for another network? I suppose there would not be much of a need. But in the real world networks aren’t everything we wish they were. Sometimes internet providers can only offer so much latency, or they go down from events taking place in the area.
Sometimes it is more cost effective to put an application on one ISP and the main bulk of your network on another. There is also the possibility that you have a physically different connection to a network resource and pathway you own and control. Still another scenario is for when networks come and go based on where you might be. The router maybe a moving device and thus different wireless networks come and go. They don’t fail exactly, they just are not there for awhile.
MultiWAN Overview:
There is a lot to cover so make sure you read slowly. This article series will illustrate a scenario that will have several moving parts. You will not implement everything because your environment is different and custom to you. This means you will not be able to simply copy/past the examples. You will need to add, remove, or customize what has been presented. To do that, you will need to understand the mono sized router example.
The example shows a single router having many WAN connections. You will not have this exact arrangement. Do you have LTE? If not, do not implement that section of the example. A best effort has been made to create a single example that can easily shed various parts that are not needed. This article assumes a VLAN environment. So, consider that a requirement in your learning journey.
Disclaimer:
What follows is my best understanding of how to implement the stated goals in RouterOS v7 based on the generous feedback from many forum community members. I am a student and spend time in the forums to learn and give back when I can. I am not an expert nor am I even a forum guru as my forum title humorously states. There are far more qualified persons in attendance. My skill is taking what others have shared and then building a presentation around their thoughts and techniques. Thank you. Note that this article is new and has many mistakes. It will be updated many times until the community considers it the gold standard.
