Chapter 12

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Unformatted text preview: es ro uters names suggest their lo catio ns (o f tentimes they use the same three character abbreviatio ns yo u’d see in airpo rts). Lo o k clo sely at the ho sts in ho ps 3 thro ugh 7. The subdo mains dub20, lo n11, lo n01, jf k02, and bo s01 suggest the packets are go ing f ro m Dublin, then east to Lo ndo n, then west to New Yo rk City (Jo hn F. Kennedy Internatio nal Airpo rt), then no rth to Bo sto n. That’s a lo ng way to travel in a f ractio n o f a seco nd! Ho p 4 is at tinet.net, but ho p 5 is at co gentco .co m (lo o k them up o nline and yo u’ll f ind o ut that co gentco .co m, like tinet.net, is also an ISP ). That suggests that between tho se ho ps peering is taking place and traf f ic is handed o f f f ro m carrier to carrier. Ho p 8 is still co gentco .co m, but it’s no t clear who the unnamed ro uter in ho p 9, 38.104.218.10, belo ngs to . We can use the Internet to sleuth that o ut, to o . Search the Internet f o r the phrase “IP address lo o kup” and yo u’ll f ind a bunch o f to o ls to track do wn the o rganizatio n that “o wns” an IP address. Using the to o l at whatismyip.co m, I f o und that this number is registered to P SI Net, which is no w part o f co gentco .co m. Ro uting paths, ISP s, and peering all revealed via tracero ute. Yo u’ve just perf o rmed a so rt o f netwo rk “CAT scan” and lo o ked into the veins and arteries that make up a po rtio n o f the Internet. P retty co o l! If yo u try o ut tracero ute o n yo ur o wn, be aware that no t all ro uters and netwo rks are tracero ute f riendly. It’s po ssible that as yo ur trace hits so me ho ps alo ng the way (particularly at the start o r end o f yo ur jo urney), three “*” characters will sho w up at the end o f each line instead o f the numbers indicating packet speed. This indicates that tracero ute has timed o ut o n that ho p. So me netwo rks blo ck tracero ute because hackers have used the to o l to pro be a netwo rk to f igure o ut ho w to attack an o rganizatio n. Mo st...
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This document was uploaded on 01/31/2014.

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