How to Set Up Redundant ISPs

Help!

I am looking for advice on how to set up some redundancy w.r.t. my ISP.

I host my company's website on my own web server that is physically located in my office. My domain (let's call it domain.com), is parked at Network Solutions. Their DNS servers point to the fixed IP on my server's modem. I use Time Warner's business class cable as my ISP.

I want to set up a backup ISP (one using DSL) so if/when Time Warner's service goes down, people who type in domain.com will still be able to access my web server through this backup ISP. This backup will rarely be used - I do not want to pay big bucks for a high-speed SDSL service. I was thinking of signing up for a $50 a month ADSL plan with a fixed IP.

What do I need to do to set things up so my domain goes through Time Warner, but if TW crashes I can switch it to use this backup ISP?

Thanks!!
Mr. Chip

 

You have at least two concerns:

• A backup ISP connection. This will work if they are different; for example, you unlikely can have a backup DSL connection because all of the ISPs offering the service are purchasing space from the same phone company. If RR DSL goes down, all other DSL ISPs from your Central Office will be down. Therefore, your alternate provider should be cable or some other physicly distinct broadband media.
  
• Relatedly, there are routers that would automaticly switch for you. Linksys offers one or two models that would do this; so do other router companies.
  
• Even though you are using a fixed IP, the next issue is updating DNS servers so others can find you. Obvioiusly you will no maintain a static IP address when you use a backup ISP provider.
  
  In order to keep DNS entries clean for your clients, use a DynDNS service. There are several free ones; Google for them. This way when your ISP changes (hence your IP changes) yoiu need only inform the DynDNS service and your clients can find you. This can also be automated; see the DynDNS providers for assistance.

 

I received this as a PM but I think it better here:

Thank you Bill! I just posted the question under networking as well. I have a few points to clarify.

1. Sorry I wasn't clear. My main ISP is cable (Time Warner's Road Runner cable). This is why I want the backup to be a DSL service.

I think I may be able to handle this with my firewall. I use a NetScreen 5 hardware firewall that sits between my cable modem and my server. I am pretty sure I could also plug in a DSL modem into the Netscreen so I can have two "inputs ". Do you think this would be best or should I have a single router that takes the cable and DSL inputs and connects to the NetScreen with one connection?

Are you saying that a Fixed IP would not work because if I needed to make a change in the DNS records that change would take 24-72 hours to propagate across the net?

Is NoIP an example of a fee-based DynDNS service? I have used them for several years but have found that there is some technical issue that makes it difficult for my domain's name to resolve in the address bar.

I am open to paying a fee, even $100 - $200 a year, to get the highest quality DynDNS service. Do you have any recommendations?

Bill,

Here is another idea. Let me know if you think this would work.

Network Solutions lets me list 4 or more DNS servers for my domain.com. What if I set up the first two DNS servers to be Time Warner and the second two to be Covad? So my record would look like this:

DNS1: TimeWarner1
DNS2: TimeWarner 2
DNS3: Covad 1
DNS4: Covad 2

If someone types domain.com, would they first try TimeWarner 1 and 2? If TW was down, would they then try DNS3 and 4?

Thanks so much for you help!!!
Mr. Chip

 

I use http://dyndns.com for all my static IP sites. In each sites setup page there is an "offline" URL option that allows me to specify what server to go to next (can be the same one using a second nic) if my main were down. Works like a charm.

Cost = $35.00 per year

<add>

It roll's over instantly. If rolled-over, your viewer's wiil see the IP of your backup route in their address bar instead of your registered name even though they entered domain.com in their browser. If that's a problem with you....I don't know?

I'd post screenies but they appear disabled.

 

This may be a heretical thing to say, but I think in many instances automatic fail-over causes more problems than it fixes.

If you need 24x7 access and being down for more than 10 minutes starts costing you significant money, then automatic fail-over is the only way to go.

I would argue that for many SMEs the loss of internet connect for an hour is manageable and the cost of such outages is less than that of systems you put in place to prevent them.

With that in mind, the way I would look to handle this issue is to configure your router for one ISP and then backup the router config as ISP_1_config. Then set up the router to work with the other ISP and backup the router config as ISP_2_config. Then restore ISP_1_config. Then if ISP 1 failed, you manually upload ISP_2_config and thereby switch to ISP 2.

This system is easy to test, is simple, and doesn't rely on automatic connection status detection.

If you want to de-skill it, buy two identical routers. Install ISP_1_config on one router and ISP_2_config on the other. If ISP 1 fails, swap routers.

 

Would it not be easier to pay for a decent hosting service? Most hosting companies would have all the fall-over stuff in place. Startlogic are very good, but there are many more.

Regards,
Del