Redundant Internet Access?

Supp0rtLinux asks: "In order to meet uptime requirements and SLAs, we decided to get redundant T1's with BGP. We already had two Cisco 7200 routers and a T1. After the ISP turned up the additional circuit and we tested everything on our end, all seemed fine. But when the CO lost power and the generator failed, we had no access for 16+ hours. This prompted some investigations which revealed that yes, we did in fact have a redundant T1 with BGP setup and local redundant routers with separate UPS... on our side. However, on their side both our feeds were plugged into the *same* switch which was on the same PDU which happened to be in the same CO and was on the same sonet. And they were charging us for redundancy! Six month later, we have a truly redundant BGP setup. Each feed goes to separate CO's with the primary to the local one. This makes for separate physical switches, separate power, and we have confirmed we're on physically separate sonets. Now, the only true single point of failure is the physical cabling in the street, but in CA that doesn't get damaged very often. To those of you on Slashdot who know what I'm talking about: are your circuits truly redundant? What have your experiences in network redundancy been? How have you gotten past the sales guy to a tech that knows what redundancy really means? Have you been able to prove your redundancy? Have you found yourself paying for something that you weren't really getting?"

Comments

Odds are You Can't

[bill_mcgonigle]

If you know enough to get diverse lines from two CO's when you buy circuits nothing says they will stay that way. You have to constantly re-prove it at the best interval you can handle.

If you get diverse paths to multiple CO's those CO's may share a common backhaul to the next more metropolitan area.

In most locations you can't get lines from anybody but the local telco, and all the lines run together.

In most locations if you can get lines from different providers they run along the same poles.

Most companies (small) can't get a big enough address block to get a route.

Many ISP's won't cooperate to "help each other" for you to use the BGP route if you have a big enough company to get a network. If there are only a few ISP's in your area this is even more true.

You need to at least run lines out different ends of your buildings, preferably you should have separate buildings with different power, etc. Then if the regional power goes out you need big generators at both buildings.

See, it's super expensive to actually get real redundancy. Try turning the problem around.

Rent some server space at different data centers in different areas of the country. Use a round-robin DNS or better. Take advantage of the new fast-updates to the .COM and .NET zones. Think of your office as a leaf node.

It's cheaper to pay for the bandwidth back to your office than it is to go for redundancy there.