Connecting 2 different Internet providers to your home or office can provide a number of benefits:
- connection fail-over, increasing availability (best compatibility, since only 1 network route provided from your office to a remote site, and thus most likely to work reliably)
- load balancing, increasing total bandwidth (2 routes available, which can confuse secure sites, and SOHO devices usually have practical issues)
- reducing Internet access cost by replacing 1 expensive provider with 2 cheaper, perhaps less-reliable or slower providers.
How you connect with 2 different ISPs depends on whether you want to buy or build …
Here’s 3 options to consider:
1. DIY with Linux iptables
- assemble a linux machine with 3 network interfaces (WAN1, WAN2, LAN)
- read the iptables page on split access and multipath routes, understanding that you are getting routing-based stickiness
- do some testing and tweaking of weights and other configuration items.
You don’t have to be a network engineer to get this working, but you should know things like static routing with the linux route command, to have a reasonable chance of success.
I’d suggest investing at most 4 hours in a project like that, then move on to one of the next options.
2. Use an Existing Open Source Project
- pfSense – based on FreeBSD. Dual-WAN Load Balancer FAQ, Dual-WAN Router Tutorial.
- Untangle is a subscription-pay but 95% Open Sourced software firewall with WAN failover ($5+/month) or WAN load balancing ($10+/month) modules
- m0n0wall, based on FreeBSD, is working on multi-WAN support
- LokiWall1 for Linux (2006)
- LokiWall2 for Linux (coming soon)
3. Buy a Dual-Wan Router Appliance
There are several SOHO appliances available for under $350.00:
- Cisco (LinkSys) RV042 and RV082 (fanless, size of a hardcover book, is export-restricted, requires a free online support account and approval of 3 EULAs to download drivers.) I have used the RV082 for a month, and noticed: the built-in switch ports cannot drive cables longer than about 15 meters, the default failover probe settings are 5x for 30 seconds, which is too long, so I use 3x for 15 seconds. Otherwise it seems to work ok with two WAN connections, one fiber and the other DSL, though failback is not supported and failover is not logged. The average IT employee or power user can configure the web-based admin screens with no training.
- Netgear FVX538 and FVS336
- Netgear FVS124G (Discontinued)
- HotBrick LB-2 (XinCom XC-DPG502?)
- Peplink
Most, if not all appliances, are just linux or BSD embedded systems. But appliances are pre-tested, nicely packaged, and have a friendly web-based UI and technical support.
Also, an appliance will use less power and emit less noise than the typical desktop PC running linux.
Unfortunately, it’s hit-or-miss whether your appliance (or it’s firmware version) will work reliably. Most blogs report less than glowing results, especially with load balancing.
tomshardware.com: Dual WAN router suggestions needed (2008)
dslreports.com: Best Dual Wan Router? (2007)
Advantages/Disadvantages of Dual Wan Routing
linuxquestions.com: Script to Load Balance two ISPs with ip route & ip rules
mikrotik.com
Soekris