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.To do that I look up the list of top level domainnames on page 379 of the 1997 edition of _DNS and BIND_.For Botswana it s bw.So I enter it at theprompt, remembering -- this is VERY important -- to put a period after the domain name:> bw.Server: swcp.comAddress: 198.59.115.2Non-authoritative answer:This non-authoritative answer stuff tells me that this information has been stored for awhile, so it ispossible, but unlikely, that the information below has changed.bw nameserver = DAISY.EE.UND.AC.ZAbw nameserver = RAIN.PSG.COMbw nameserver = NS.UU.NETbw nameserver = HIPPO.RU.AC.ZAAuthoritative answers can be found from:DAISY.EE.UND.AC.ZA inet address = 146.230.192.18 RAIN.PSG.COM inet address = 147.28.34NS.UU.NET inet address = 137.39.1.3HIPPO.RU.AC.ZA inet address = 146.231.128.1I look up the domain name za and discover it stands for South Africa.This tells me that the Internet is inits infancy in Botswana -- no nameservers there -- but must be well along in South Africa.Look at all thosenameservers!***********************Newbie note: a nameserver is a computer program that stores data on the Domain Name System.TheDomain Name System makes sure that no two computers have the same name.It also stores information onhow to find other computers.When various nameservers get to talking with each other, they eventually,usually within seconds, can figure out the routes to any one of the millions of computers on the Internet.***********************Well, what this tells me is that people who want to set up Internet host computers in Botswana usually relyon computers in South Africa to connect them.Let s learn more about South Africa.Since we are still in thenslookup program, I command it to tell me what computers are nameservers for South Africa:> za.Server: swcp.comAddress: 198.59.115.2Non-authoritative answer:za nameserver = DAISY.EE.UND.AC.zaza nameserver = UCTHPX.UCT.AC.zaza nameserver = HIPPO.RU.AC.zaza nameserver = RAIN.PSG.COMza nameserver = MUNNARI.OZ.AUza nameserver = NS.EU.NETza nameserver = NS.UU.NETza nameserver = UUCP-GW-1.PA.DEC.COMza nameserver = APIES.FRD.AC.zaAuthoritative answers can be found from:DAISY.EE.UND.AC.za inet address = 146.230.192.18UCTHPX.UCT.AC.za inet address = 137.158.128.1HIPPO.RU.AC.za inet address = 146.231.128.1RAIN.PSG.COM inet address = 147.28.34MUNNARI.OZ.AU inet address = 128.250.22.2MUNNARI.OZ.AU inet address = 128.250.1.21NS.EU.NET inet address = 192.16.202.11UUCP-GW-1.PA.DEC.COM inet address = 204.123.2.18UUCP-GW-1.PA.DEC.COM inet address = 16.1.18APIES.FRD.AC.za inet address = 137.214.80.1***********************Newbie note: What is inet address = 137.214.80.1 supposed to mean? That s the name of a computer on theInternet (inet) -- in this case APIES.FRD.AC -- in octal.Octal is like regular numbers except in base 8 ratherthan base 10.All computer names on the Internet must be changed into numbers so that other computerscan understand them.**********************Aha! Some of those nameservers are located outside South Africa.We see computers in Australia (au) andthe US (com domain).Next, we exit the nslookup program with the command ^D.That s made by holding down the control key while hitting the small d key.It is VERY IMPORTANT to exit nslookup this way andnot with ^C.Next, we take one of the nameservers in South Africa and ask:->whois HIPPO.RU.AC.ZA[No name] (HIPPO)Hostname: HIPPO.RU.AC.ZAAddress: 146.231.128.1System: SUN running SUNOSDomain ServerRecord last updated on 24-Feb-92.To see this host record with registered users, repeat the command with a star ('*') before the name; or, use'%' to show JUST the registered users.The InterNIC Registration Services Host contains ONLY Internet Information (Networks, ASN's, Domains,and POC's).Please use the whois server at nic.ddn.mil for MILNET Information.Kewl! This tells us what kind of computer it is -- a Sun -- and the operating system, Sun OS.Now, just for variety, I use the whois command with the numerical address of one of the nameservers.Thisdoesn t always give back the text name, but sometimes it works.And, voila, we get:->whois 146.230.192.18[No name] (DAISY1)Hostname: DAISY.EE.UND.AC.ZAAddress: 146.230.192.18System: HP-9000 running HP-UXDomain ServerRecord last updated on 14-Sep-94.Ah, but all this is doing so far is just telling us info about who is a nameserver for whom.Now how aboutdirectly mapping a route from my computer to South Africa? For that we will use the traceroute command.************************Netiquette tip: The traceroute program is intended for use in network testing, measurement andmanagement.It should be used primarily for manual fault isolation, like the time I couldn t email my friend inNorthern Ireland.Because of the load it could impose on the network, it is unwise to use traceroute fromautomated scripts which could cause that program to send out huge numbers of queries.Use it too muchand your ISP may start asking you some sharp questions.************************************************YOU COULD GO TO JAIL WARNING: If you just got an idea of how to use traceroute for a denial ofservice attack, don t call your favorite journalist and tell him or her that you are plotting a denial of serviceattack against the ISPs that serve famous people like Bill Clinton and Carolyn Meinel!:-) Don t write that script.Don t use it.If you do, I ll give another interview to PC World magazine(http://www.pcworld.com/news/newsradio/meinel/index.html) about how a three-year-old could run theattack.And if you get caught we ll all laugh at you as you get hustled off in chains while your journalistfriend gets a $250K advance on his or her book deal about you.************************I give the command:->whereis traceroutetraceroute: /usr/local/bin/tracerouteOK, now we re ready to map in earnest.I give the command:->/usr/local/bin/traceroute DAISY.EE.UND.AC.ZAAnd the answer is:traceroute to DAISY.EE.UND.AC.ZA (146.230.192.18), 30 hops max, 40 byte packets1 sisko (198.59.115 [ Pobierz całość w formacie PDF ]