Ask Slashdot: Best Connect Scheme For a 2-ISP Household?

c_petras writes "I just had DSL installed (a 19,000 ft run — Woo Hoo!) to act as a backup to my regional WiFi connection. How should I configure my home network so I don't have to swap the cable from one ISP's router to the other to maintain a good connection? Is it as simple as getting another router and plugging the two ISPs in? Is there a more elegant solution that would not require the use of three separate boxes and associated wall warts?"

What I did.

[grub]

I did this a couple of years ago with DSL and cable. My choice was to use OpenBSD's Equal-Cost Multipath Routing [openbsd.org]. I've seen other hardware devices that accept two broadband connections but the OpenBSD option was much more elegant and allowed some good granularity in traffic control (ie.: traffic to my cable ISP's billing page may as well go through the cable connection)

I had a couple of lines in pf.conf as so:

table <route_cable> persist file "/etc/route_cable"
table <route_dsl> persist file "/etc/route_dsl"

then would force the network ranges/IPs contained through the appropriate interface.

I dumped the DSL about a year ago but this worked very well for me. YMMV. Mail me if you'd like more info/tips.

Re:What router/firewall?

[Anonymous Coward]

http://lmgtfy.com/?q=dual+wan+router

Re:What router/firewall?

[ryanov]

The one that my church uses has a 2 WAN option:

http://www.cisco.com/en/US/products/ps9926/index.html [cisco.com]

Not a home class one, but only $260.

Re:What I did.

[Bastardchyld]

I recommend pfSense 2.0 RC3 to be specific. It has a new ability to use Multiple WANs, you can even weight them based on which has a better connectivity and balance traffic over both. Giving you load balancing and failover between both connections.

Re:dd-wrt

[Anonymous Coward]

DD-WRT was my first thought for something that could do this with out costing a fortune but Mesh Networking isn't even close to what the OP is asking about.

http://www.dd-wrt.com/wiki/index.php/Dual-WAN_for_simple_round-robin_load_equalization

or

http://www.dd-wrt.com/wiki/index.php/Dual_WAN_with_one_as_standby_backup

Re:What I did.

[pz]

I'm not the highly informative poster above, but can readily speculate justifications nevertheless: (1) reliability, reliability, reliability, (2) cost differential between the two services during different times of the day or days of the week, (3) to maximize available bandwidth if one or the other connection bogs down from one's neighbor, (4) to be able to tell one or the other service to frell off on a moment's notice, (5) to be able to load down one ISP's connection, say with a large file transfer, and have the local network still remain responsive by automatically switching everything else to the other ISP, etc.

I've implemented a related, but certainly not identical, system in my home with two wireless APs running two independent networks feeding a single cable connection. Robustness was the primary motivation.

You won't get what you think....

[EriktheGreen]

If what you're looking for is A) Fail-over, so if one ISP or line is down you use the other or B) The ability to reach selected IP addresses via one ISP or the other, a dual WAN setup will work for you using one of the dual WAN setups people have mentioned. They're basically hacks that masquerade your desktop behind a public IP address from whichever provider you happen to be using at any moment. They don't allow asymmetric traffic (can't send packets out one ISP and receive via the other ISP) and they'll possibly screw up any security protocol or site that expects to see packets coming from a single IP and port address. This is handy, but only slightly more convenient than moving the cable yourself and re-issuing a DHCP request. Forget about aggregating bandwidth, you won't get that.

If you're thinking that hooking up both ISPs to a router will let you use whichever one is faster for any site when you click on it, you can't do that without a ton of work (and for the most part without being an ISP). The problem is that although a routing protocol exists on the global internet that would let your router figure out which path is best to each network prefix, to use it you have to have your own routing block (an aggregate of multiple network addresses) to announce to the world (which you can't get) and you have to have a router capable of holding and processing the global BGP table in real time... you don't have this.

If only all our home routers could speak a multi path routing protocol with low overhead, every single packet we sent would take the best path to its destination, all our computers would automatically fail over to other connections, we could add bandwidth by plugging in another wire, we could add and remove bandwidth in real time as needed, and we could migrate between internet providers without re-numbering our IP addresses. Things like mobile apps would be much easier to write.. no need to use a central server to pass data to a mobile, just send the packets to its IP and the routing protocol would send them on to wherever it's connected in the net.

I look forward to the day when the Internets evolve to permit multiple pathing for data in real time. Too bad technological development of Internet protocols seems to have slowed and become heavily political.

Erik