[TriLUG] What does he mean?

[Kevin Otte]

I wonder if the acronym soup got messed up and he meant BGP routing 
issue. The large players on the Internet are organized in Autonomous 
Systems (ASes), each of which announce to each other what IP addresses 
it has within it.

If you want to get a feel for how these systems are connected, you can 
visit http://bgp.he.net/ and put an IP address in the search field. It 
will come back with which AS is announcing that prefix. Click on the AS 
number for more information.

In your example I find that one of bbc.com's IP addresses
212.58.244.18 is being announced by AS2818. In the details page you can 
click one of the Graph tabs and see how the ASes are hooked together.

There are any number of ways in which this can go wrong. The 
interconnection between two ASes can accidentally get severed and the 
route to where you're going can become too long or completely 
unavailable. An AS may stop announcing a prefix that it is supposed to 
be, or it may start announcing a prefix that it is not supposed to be. 
Such errors are usually detected fairly quickly and put right, but not 
before their effects are felt pretty widely. Google appeared to drop off 
the 'net briefly a couple times: in 2008 when a Pakistani ISP started 
announcing their prefixes in an attempt to censor them 
[http://www.renesys.com/2008/02/pakistan-hijacks-youtube-1/], and again 
in 2012 when a router at an Indonesian ISP went mega-sideways 
[http://blog.cloudflare.com/why-google-went-offline-today-and-a-bit-about].

After looking at all this, one might conclude that it's a miracle the 
Internet works at all. I agree. It's a wondrous miracle of human 
achievement that I hope continues to grow and prosper for years to come.

-- Kevin

On 03/15/2014 09:59 PM, James Jones wrote:
> Hi,
>
> Recently Comcast had a problem. From anywhere within their network
> system, you could not access bbc.com/news. My brother emailed me about
> it. I am on Uverse plus I have access to Time Warner and a server in
> the cloud ( not sure of isp on that one ). I had no problem accessing
> bbc.com on Uverse and time warner. Eventually, I ended up on a comcast
> forum which had many users complaining about no bbc access.
>
> At one point, Jlivingood, a moderator of the forum, came forward with
> this remark:
>
> "This is some kind of TBD routing issue. We are investigating it now.
> JL
> National Engineering & Technical Operations "
>
> And later -- he wrote, " Appears a connected network was announcing a
> bad route, which we are now ignoring until we get to the bottom of
> this. Should be resolved right now, but still chasing root cause on
> the bad / erroneous announcement."
>
> Soon after this comment, my brother in Florida on comcast, wrote that
> bbc was back on comcast.
>
> I would like to understand what Jason Livingood means by "a connected
> network was announcing a bad route". I am assuming the TBD means "to
> be decided". If there is another meaning for that, please chime in.
>