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-rw-r--r--chapter_16.xml127
1 files changed, 81 insertions, 46 deletions
diff --git a/chapter_16.xml b/chapter_16.xml
index b8872f2..c95e57a 100644
--- a/chapter_16.xml
+++ b/chapter_16.xml
@@ -84,26 +84,16 @@ packets
2 10.0.0.1 (10.0.0.1) 7.642 ms 8.019 ms 6.006 ms
3 68.1.8.49 (68.1.8.49) 10.446 ms 9.739 ms 7.003 ms
4 68.1.8.69 (68.1.8.69) 11.564 ms 6.235 ms 7.971 ms
- 5 dalsbbrj01-ae0.r2.dl.cox.net (68.1.0.142) 43.859 ms 43.287 ms
-44.125 ms
- 6 dpr1-ge-2-0-0.dallasequinix.savvis.net (204.70.204.146) 41.927 ms
-58.247 ms 44.989 ms
- 7 cr2-tengige0-7-5-0.dallas.savvis.net (204.70.196.29) 42.577 ms
-46.110 ms 43.977 ms
- 8 cr1-pos-0-3-3-0.losangeles.savvis.net (204.70.194.53) 78.070 ms
-76.735 ms 76.145 ms
- 9 bpr1-ge-3-0-0.LosAngeles.savvis.net (204.70.192.222) 77.533 ms
-108.328 ms 120.096 ms
-10 wiltel-communications-group-inc.LosAngeles.savvis.net
-(208.173.55.186) 79.607 ms 76.847 ms 75.998 ms
-11 tg9-4.cr01.lsancarc.integra.net (209.63.113.57) 84.789 ms 85.436
-ms 85.575 ms
-12 tg13-1.cr01.sntdcabl.integra.net (209.63.113.106) 87.608 ms
-84.278 ms 86.922 ms
-13 tg13-4.cr02.sntdcabl.integra.net (209.63.113.134) 87.284 ms
-85.924 ms 86.102 ms
-14 tg13-1.cr02.rcrdcauu.integra.net (209.63.114.169) 85.578 ms
-85.285 ms 84.148 ms
+ 5 dalsbbrj01-ae0.r2.dl.cox.net (68.1.0.142) 43.859 ms 43.287 ms 44.125 ms
+ 6 dpr1-ge-2-0-0.dallasequinix.savvis.net (204.70.204.146) 41.927 ms 58.247 ms 44.989 ms
+ 7 cr2-tengige0-7-5-0.dallas.savvis.net (204.70.196.29) 42.577 ms 46.110 ms 43.977 ms
+ 8 cr1-pos-0-3-3-0.losangeles.savvis.net (204.70.194.53) 78.070 ms 76.735 ms 76.145 ms
+ 9 bpr1-ge-3-0-0.LosAngeles.savvis.net (204.70.192.222) 77.533 ms 108.328 ms 120.096 ms
+10 wiltel-communications-group-inc.LosAngeles.savvis.net (208.173.55.186) 79.607 ms 76.847 ms 75.998 ms
+11 tg9-4.cr01.lsancarc.integra.net (209.63.113.57) 84.789 ms 85.436 ms 85.575 ms
+12 tg13-1.cr01.sntdcabl.integra.net (209.63.113.106) 87.608 ms 84.278 ms 86.922 ms
+13 tg13-4.cr02.sntdcabl.integra.net (209.63.113.134) 87.284 ms 85.924 ms 86.102 ms
+14 tg13-1.cr02.rcrdcauu.integra.net (209.63.114.169) 85.578 ms 85.285 ms 84.148 ms
15 209.63.99.166 (209.63.99.166) 84.515 ms 85.424 ms 85.956 ms
16 208.186.199.158 (208.186.199.158) 86.557 ms 85.822 ms 86.072 ms
17 sac-main.cwo.com (209.210.78.20) 88.105 ms 87.467 ms 87.526 ms
@@ -290,6 +280,77 @@ general purpose Internet scanners.
</section>
+<section>
+<title>host</title>
+
+<para>
+Often network problems stem from a failure of DNS (Domain Name Service)
+which maps domain names to IP addresses. An easy way to perform quick
+DNS lookups is the <application>host</application>(1) command. When
+this is run, your computer will perform a few common DNS lookups and
+return the results.
+</para>
+
+<screen><prompt>darkstar:~# </prompt><userinput>host www.slackware.com</userinput>
+www.slackware.com is an alias for slackware.com.
+slackware.com has address 64.57.102.34
+slackware.com mail is handled by 1 mail-mx.cwo.com.
+</screen>
+
+</section>
+
+<section>
+<title>dig</title>
+
+<para>
+More complex DNS lookups can be manually performed with the
+<application>dig</application>(1) tool. <application>dig</application>
+is "the meanest dog in the pound" when it comes to troubleshooting DNS
+issues. With this tool, you can perform virtually any DNS lookup from
+reverse lookups to A, CNAME, MX, SP, TXT records and more. There are
+far too many command-line options and lookup types to go into depth
+here, but the man page lists all the common use cases.
+</para>
+
+<screen><prompt>darkstar:~# </prompt><userinput>dig @207.69.188.185 www.slackware.com a</userinput>
+
+; &lt;&lt;&gt;&gt; DiG 9.4.3-P4 &lt;&lt;&gt;&gt; @207.69.188.185 www.slackware.com a
+; (1 server found)
+;; global options: printcmd
+;; Got answer:
+;; -&gt;&gt;HEADER&lt;&lt;- opcode: QUERY, status: NOERROR, id: 57965
+;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 0
+
+;; QUESTION SECTION:
+;www.slackware.com. IN A
+
+;; ANSWER SECTION:
+www.slackware.com. 86400 IN CNAME slackware.com.
+slackware.com. 86400 IN A 64.57.102.34
+
+;; AUTHORITY SECTION:
+slackware.com. 86400 IN NS ns2.cwo.com.
+slackware.com. 86400 IN NS ns1.cwo.com.
+
+;; Query time: 348 msec
+;; SERVER: 207.69.188.185#53(207.69.188.185)
+;; WHEN: Sat Jul 3 16:25:10 2010
+;; MSG SIZE rcvd: 105
+
+</screen>
+
+<para>
+Let's take a took at the command-line options used above. The
+<arg>@207.69.188.185</arg> argument tells
+<application>dig</application> what DNS server to query. If it is not
+specified, <application>dig</application> will simply use whatever
+servers are listed in <filename>/etc/resolv.conf</filename>. The
+<arg>a</arg> argument at the end is the type of DNS record to lookup.
+In this case we looked for an "A" record which returned an IPv4 address.
+</para>
+
+</section>
+
</section>
<section><title>Web Browsers</title>
@@ -495,32 +556,6 @@ lftp ftp.osuosl.org:/pub/slackware/slackware-current> <userinput>bye</userinput>
</section>
<section>
-<title>NNTP Clients</title>
-
-<para>
-Once upon a time when the Internet was young, before the World Wide Web
-was invented and no one had heard of hyperlinks, everyone retrieved
-their news and information through a service known as Usenet using the
-NNTP protocol. It remains today a useful knowledge base of information
-on an incredible variety of subjects, but if you wish to access this
-information, you're going to need a proper client. Slackware includes
-a number of NNTP clients with both console and graphical interfaces,
-but we'll only detail the console tools here. Popular graphical news
-readers include <application>knode</application> and
-<application>pan</application>.
-</para>
-
-<section><title>tin</title>
-
-</section>
-
-<section><title>slrn</title>
-
-</section>
-
-</section>
-
-<section>
<title>rsync</title>
<para>