Redundant internet using a Tomato capable router

TLDR; Get a tomato-capable router. Use its multi-WAN function to fuse connections from two ISPs together

Rant

Internet situation in India is bad. I am currently living in New Delhi but was based in UK for the last 5 years. I had got used to 50mbps and even 100mbps unlimited connections. After moving back I was a bit surprised to learn things hadn't moved on much at all since I left. Only a couple of ISPs (Airtel and MTNL) in Delhi were capable of providing stable connections. Fast, unlimited plans were nowhere to be found. I was frequently paying more than Rs4,000 per month for internet, due to all the additional data I was using. This was on Airtel's 8mbps plan which came with a 80GB 'FUP'¹. I was paying far less for completely unlimited 50mbps/100mbps plans back in UK!

So I bit the bullet and got a connection from a local ISP called 'Excitel'. I had never heard of them and was dubious about their ability to provide a reliable connection. But their 50mbps unlimited connection at Rs 800 per month was enticing enough. Four guys turned up to do the installation. The internet came over a LAN cable flung from the nearest khamba². I had last got internet this way more than 10 years ago³. As expected the connection was very unreliable. I was raising several support tickets each week to get the connectivity restored each time it went down. I had wisely not disconnected Airtel yet. So whenever Excitel went down I could switch wifi connections and start using Airtel for a few hours. So I now had unlimited internet for about Rs1800 per month for the two connections(after switching to Airtel's lowest 10GB plan). But the manual switching of wifi connections was getting annoying.

After a few months of putting up with this I finally put a solution in place. I have been running Tomato firmware⁴ on my router since many years. And recently the developers added multi-WAN functionality to the firmware. Perfect. I updated the router and made the required configuration changes and lived happily ever after.

How-To

Here are the steps to follow if you find yourself in a similar situation -

1. Get a router that supports Tomato firmware (anything that has a broadcom chip inside). Get one of these if you are unsure. I am using a Netgear WNR3500L v2⁵.

• Download tomato for your router from here if you want the new slick UI or from here if you like the old school look.
• Open your router settings page. Usually at 192.168.1.1 or 192.168.0.1.
• Find the option to upgrade firmware and upload the tomato firmware file.
• Wait for the firmware to be installed and pray your router doesn’t get bricked.
• Once the new firmware is installed go to 192.168.1.1 and navigate to Advanced > VLAN on the sidebar
• Uncheck port 1 for LAN(br0)
• On the last row select 'WAN2' from the drop-down and select port 1. Click Add. This will designate Port 1 to be used as your second WAN port. Your screen should be looking like the screenshot below now.
• Click save and navigate to Basic > Network
• Select '2WAN' for number of WAN ports option.
• Configure WAN 1 details as provided by your ISP. Connection type would probably be DHCP or pppoe with a user name and password.
• For WAN 2 set the connection type to DHCP and load balance weight to 0.
• Configure your wifi name and password on the same page. Click save and wait for the router to reboot.
• Connect an ethernet cable from one of the LAN ports on your Airtel/MTNL modem to port 1 on the tomato router.
• Done

You should now have an always up connection which automatically falls back to using your 2nd ISP when the first one goes down.

Notes

• You can also use another open-source firmware - dd-wrt to achieve similar results. If you already have a router compatible with dd-wrt you should give it a shot first. I don't have any experience with it so please get google to help you with this.
• When the router is using ISP2 with the above setup you are accessing the internet via two devices. This will cause a 'double-NAT' situation, which can cause problems for services such as torrents and VOIP. An easy fix would be to put the IP address of the tomato router in 'DMZ' on the modem/router for ISP2.
• It is possible to have the router send push alerts to your phone every time one of the connections goes down. I will write a separate post on how to set this up.
• Airtel has upped its smallest plan's data from 10 to 25 GB now so I am less concerned about going over in the periods Excitel is down. However it would still be a good idea to keep track of usage on the backup connection.

Home