Another Time Warner Cable Outage: RoadRunner Blocks BlueHost? UPDATED

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Home / Another Time Warner Cable Outage: RoadRunner Blocks BlueHost? UPDATED

Outages are complicated by communications problems. Image by VLN

Has Time Warner Cable blocked bluehost.com sites? According to bluehost technicians, yes. According to Time Warner technicians, however, the answer is a little less clear.

What’s bluehost?

Bluehost is a website hosting provider that provides domain names and hosting for independent websites. (Full disclosure: Decoded Science is hosted on BlueHost’s servers.)

What’s RoadRunner?

For those of you who are not already aware, RoadRunner is the Internet connectivity option offered by Time Warner Cable. TWC recently suffered a recent nationwide outage, but the current problem is apparently limited to only websites hosted at bluehost.

Time Warner Cable, What’s the Problem?

What do you do when the technician can’t help you? Image by 7rains

According to the two technicians I spoke with at bluehost, TWC is blocking all sites that are hosted on the bluehost servers. I also spoke to two technicians at Time Warner Cable, but the kindest thing I can say is that they were unable to provide adequate answers. At various times, I was told by the technicians that TWC is having an Internet connectivity problem with no ETA for resolution, and that they’re having a DNS problem which should be resolved soon, and that I should just reboot my modem to see if that brings my Internet access back up. (The same Internet access I was using to live-chat with the technician.)

DNS Servers: The Likely Culprit

It’s unlikely that Time Warner is having an ‘Internet connectivity problem’ that only affects a set of sites belonging to a single webhost. My money is on a DNS problem. Domain Name System servers are provided by an ISP (Internet Service Provider) to its customers. DNS servers resolve website names to IP (Internet Protocol) addresses. Each website is assigned an IP address, which marks its place on the server where it is hosted – think of it like a Zip Code, and the DNS server like your local post office.

When you type in, “www.decodedscience.org,” that means nothing to your browser, but your DNS server takes the URL, or web address, and compares it to its database to figure out that the IP address is 66.147.244.194, and sends your request on to the appropriate hosting server to bring you the webpage you want to view. If Time Warner has a problem with bluehost IP addresses in its Domain Name Servers, all Time Warner customers will have difficulty accessing any site that is affected. The fact that the problem is intermittent makes it even more likely – if the problem is only on a single server of many, customers will only experience the problem when they hit the bad server.

Google’s DNS Servers are available for customers having problems. Image by VLN

What Can You Do If You’re Affected?

Once you’ve called Time Warner to complain, and find that you’re still faced with the problem, what then? The easiest solution is to use non-local DNS servers, such as Google’s Public Name Servers. (This is what worked for me, but YMMV.) Don’t forget to write down your DNS server IPs if you aren’t pulling them by DHCP, and be careful when making changes to your settings. If you don’t know what you’re doing, and don’t feel comfortable following the detailed directions provided by Google, ask a more tech-savvy person to help you out.

Monday Morning Update (November 14)

I received an interesting email from Nathan Storms at iqmetrix on this topic. According to Nathan, the problem’s root cause is a combination of two factors (not the DNS problem I hypothesized above):

1. The bad firmware update that occurred on the 7th of November was the catalyst.

2. Time Warner’s response to the original problem, deleting and recreating AS numbers, exacerbated the problem.

What are AS Numbers?

AS, or Autonomous System, numbers are best defined as follows (more at the IETF):

“The classic definition of an Autonomous System is a set of routers under a single technical administration, using an interior gateway protocol (IGP) and common metrics to determine how to route packets within the AS, and using an inter-AS routing protocol to determine how to route packets to other ASs. Since this classic definition was developed, it has become common for a single AS to use several IGPs and sometimes several sets of metrics within an AS. The use of the term Autonomous System here stresses the fact that, even when multiple IGPs and metrics are used, the administration of an AS appears to other ASs to have a single coherent interior routing plan and presents a consistent picture of what destinations are reachable through it.”

What do AS numbers have to do with the outage?

I’ll just quote Nathan here, since his explanation is simple and clear:

“They deleted and recreated entire Autonomous System (AS) numbers which represent large segments of the internet, which is one way to fix this but it is kind of like turning of the power to an entire city to turn off the power to a single street light.”

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