Any big ISP with lots of peers could cause chaos though, hell, I could - hows about I take down the bbc for a laugh??
http://www.scientology.org/
http://www.scientology.org/
I have to admit, I haven't figured this one out yet.
How would an ISP in Pakistan affect DNS in the UK pointing to a US-based website?
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I have to admit, I haven't figured this one out yet.
How would an ISP in Pakistan affect DNS in the UK pointing to a US-based website?
It's to with how the internet backbone and BGP works, an ISP advertises the routes it has to it's peers (essentially the rest of the internet). An ISP will recieve each route multiple times by different paths and then chooses the most optimal to install into the routing table (usually shortest path but some ISPs will use other criteria).
If an ISP advertises a route to which it doesn't own, then you have fun and games. It's quite common but usually is only very small scale, linx peers are forever advertising invalid routes to each other but it only affects traffic traversing certain paths usually.
However in this case a big ISP appears to have announced the route invalidly to many peers simultaneous. Essentially becasue they're near the top of the tree, this sucks in a huge amount of traffic from the rest of the internet.
It's not DNS at all, because the IP address remains the same.
EDIT: Have a play with http://bgplay.uoregon.edu/bgplay/ if you're interested in how the paths change over time...
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