said by wentlanc :

Perhaps monitoring routing tables for AS path changes would be key to picking up this kind of exploit?

cw

A handful of academic groups collect BGP routing information from cooperating ASes to monitor BGP updates that change traffic's path. But without context, it can be difficult to distinguish a legitimate change from a malicious hijacking. There are reasons traffic that ordinarily travels one path could suddenly switch to another -- say, if companies with separate ASes merged, or if a natural disaster put one network out of commission and another AS adopted its traffic. On good days, routing paths can remain fairly static. But "when the internet has a bad hair day," Kent said, "the rate of (BGP path) updates goes up by a factor of 200 to 400."

Kapela said eavesdropping could be thwarted if ISPs aggressively filtered to allow only authorized peers to draw traffic from their routers, and only for specific IP prefixes. But filtering is labor intensive, and if just one ISP declines to participate, it "breaks it for the rest of us," he said.

"Providers can prevent our attack absolutely 100 percent," Kapela said. "They simply don't because it takes work, and to do sufficient filtering to prevent these kinds of attacks on a global scale is cost prohibitive."