Chapter 12

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

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, 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, 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,, 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 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...
View Full Document

This document was uploaded on 01/31/2014.

Ask a homework question - tutors are online