00000002.htm

一份很好的linux入门资料

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*.foo.xx.&nbsp;&nbsp;&nbsp;&nbsp;MX&nbsp;100&nbsp;&nbsp;gateway.xx.&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;MX&nbsp;200&nbsp;&nbsp;fallback.yy.&nbsp;<BR>
8.&nbsp;Hostnames&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;People&nbsp;appear&nbsp;to&nbsp;sometimes&nbsp;look&nbsp;only&nbsp;at&nbsp;STD&nbsp;11,&nbsp;RFC&nbsp;822&nbsp;to&nbsp;determine&nbsp;<BR>
&nbsp;&nbsp;&nbsp;whether&nbsp;a&nbsp;particular&nbsp;hostname&nbsp;is&nbsp;correct&nbsp;or&nbsp;not.&nbsp;Hostnames&nbsp;should&nbsp;<BR>
&nbsp;&nbsp;&nbsp;strictly&nbsp;conform&nbsp;to&nbsp;the&nbsp;syntax&nbsp;given&nbsp;in&nbsp;STD&nbsp;13,&nbsp;RFC&nbsp;1034&nbsp;(page&nbsp;11),&nbsp;<BR>
&nbsp;&nbsp;&nbsp;with&nbsp;*addresses*&nbsp;in&nbsp;addition&nbsp;conforming&nbsp;to&nbsp;RFC&nbsp;822.&nbsp;As&nbsp;an&nbsp;example&nbsp;<BR>
&nbsp;&nbsp;&nbsp;take&nbsp;&quot;c&amp;w.blues&quot;&nbsp;which&nbsp;is&nbsp;perfectly&nbsp;legal&nbsp;according&nbsp;to&nbsp;RFC&nbsp;822,&nbsp;but&nbsp;<BR>
&nbsp;&nbsp;&nbsp;which&nbsp;can&nbsp;have&nbsp;quite&nbsp;surprising&nbsp;effects&nbsp;on&nbsp;particular&nbsp;systems,&nbsp;e.g.,&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&quot;telnet&nbsp;c&amp;w.blues&quot;&nbsp;on&nbsp;a&nbsp;Unix&nbsp;system.&nbsp;<BR>
&nbsp;<BR>
9.&nbsp;HINFO&nbsp;records&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;There&nbsp;appears&nbsp;to&nbsp;be&nbsp;a&nbsp;common&nbsp;misunderstanding&nbsp;that&nbsp;one&nbsp;of&nbsp;the&nbsp;data&nbsp;<BR>
&nbsp;&nbsp;&nbsp;fields&nbsp;(usually&nbsp;the&nbsp;second&nbsp;field)&nbsp;in&nbsp;HINFO&nbsp;records&nbsp;is&nbsp;optional.&nbsp;A&nbsp;<BR>
&nbsp;&nbsp;&nbsp;recent&nbsp;scan&nbsp;of&nbsp;all&nbsp;reachable&nbsp;nameservers&nbsp;in&nbsp;only&nbsp;one&nbsp;country&nbsp;revealed&nbsp;<BR>
&nbsp;&nbsp;&nbsp;some&nbsp;300&nbsp;incomplete&nbsp;HINFO&nbsp;records.&nbsp;Specifying&nbsp;two&nbsp;data&nbsp;fields&nbsp;in&nbsp;a&nbsp;<BR>
&nbsp;&nbsp;&nbsp;HINFO&nbsp;record&nbsp;is&nbsp;mandatory&nbsp;(RFC&nbsp;1033),&nbsp;but&nbsp;note&nbsp;that&nbsp;this&nbsp;does&nbsp;*not*&nbsp;<BR>
&nbsp;&nbsp;&nbsp;mean&nbsp;that&nbsp;HINFO&nbsp;records&nbsp;themselves&nbsp;are&nbsp;mandatory.&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
Beertema&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[Page&nbsp;5]&nbsp;<BR>
&nbsp;<BR>
RFC&nbsp;1537&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Common&nbsp;DNS&nbsp;Data&nbsp;File&nbsp;Configuration&nbsp;Errors&nbsp;&nbsp;&nbsp;&nbsp;October&nbsp;1993&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
10.&nbsp;Safety&nbsp;measures&nbsp;and&nbsp;specialties&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Nameservers&nbsp;and&nbsp;resolvers&nbsp;aren't&nbsp;flawless.&nbsp;Bogus&nbsp;queries&nbsp;should&nbsp;be&nbsp;<BR>
&nbsp;&nbsp;&nbsp;kept&nbsp;from&nbsp;being&nbsp;forwarded&nbsp;to&nbsp;the&nbsp;root&nbsp;servers,&nbsp;since&nbsp;they'll&nbsp;only&nbsp;<BR>
&nbsp;&nbsp;&nbsp;lead&nbsp;to&nbsp;unnecessary&nbsp;intercontinental&nbsp;traffic.&nbsp;Known&nbsp;bogus&nbsp;queries&nbsp;<BR>
&nbsp;&nbsp;&nbsp;that&nbsp;can&nbsp;easily&nbsp;be&nbsp;dealt&nbsp;with&nbsp;locally&nbsp;are&nbsp;queries&nbsp;for&nbsp;0&nbsp;and&nbsp;broadcast&nbsp;<BR>
&nbsp;&nbsp;&nbsp;addresses.&nbsp;&nbsp;To&nbsp;catch&nbsp;such&nbsp;queries,&nbsp;every&nbsp;nameserver&nbsp;should&nbsp;run&nbsp;<BR>
&nbsp;&nbsp;&nbsp;primary&nbsp;for&nbsp;the&nbsp;0.in-addr.arpa&nbsp;and&nbsp;255.in-addr.arpa&nbsp;zones;&nbsp;the&nbsp;zone&nbsp;<BR>
&nbsp;&nbsp;&nbsp;files&nbsp;need&nbsp;only&nbsp;contain&nbsp;a&nbsp;SOA&nbsp;and&nbsp;an&nbsp;NS&nbsp;record.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Also&nbsp;each&nbsp;nameserver&nbsp;should&nbsp;run&nbsp;primary&nbsp;for&nbsp;0.0.127.in-addr.arpa;&nbsp;<BR>
&nbsp;&nbsp;&nbsp;that&nbsp;zone&nbsp;file&nbsp;should&nbsp;contain&nbsp;a&nbsp;SOA&nbsp;and&nbsp;NS&nbsp;record&nbsp;and&nbsp;an&nbsp;entry:&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1&nbsp;&nbsp;&nbsp;&nbsp;PTR&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;localhost.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;There&nbsp;has&nbsp;been&nbsp;extensive&nbsp;discussion&nbsp;about&nbsp;whether&nbsp;or&nbsp;not&nbsp;to&nbsp;append&nbsp;<BR>
&nbsp;&nbsp;&nbsp;the&nbsp;local&nbsp;domain&nbsp;to&nbsp;it.&nbsp;The&nbsp;conclusion&nbsp;was&nbsp;that&nbsp;&quot;localhost.&quot;&nbsp;would&nbsp;be&nbsp;<BR>
&nbsp;&nbsp;&nbsp;the&nbsp;best&nbsp;solution;&nbsp;reasons&nbsp;given&nbsp;were:&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;-&nbsp;&quot;localhost&quot;&nbsp;itself&nbsp;is&nbsp;used&nbsp;and&nbsp;expected&nbsp;to&nbsp;work&nbsp;on&nbsp;some&nbsp;systems.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;-&nbsp;translating&nbsp;127.0.0.1&nbsp;into&nbsp;&quot;localhost.my_domain&quot;&nbsp;can&nbsp;cause&nbsp;some&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;software&nbsp;to&nbsp;connect&nbsp;to&nbsp;itself&nbsp;using&nbsp;the&nbsp;loopback&nbsp;interface&nbsp;when&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;it&nbsp;didn't&nbsp;want&nbsp;to.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Note&nbsp;that&nbsp;all&nbsp;domains&nbsp;that&nbsp;contain&nbsp;hosts&nbsp;should&nbsp;have&nbsp;a&nbsp;&quot;localhost&quot;&nbsp;A&nbsp;<BR>
&nbsp;&nbsp;&nbsp;record&nbsp;in&nbsp;them.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;People&nbsp;maintaining&nbsp;zone&nbsp;files&nbsp;with&nbsp;the&nbsp;Serial&nbsp;number&nbsp;given&nbsp;in&nbsp;dotted&nbsp;<BR>
&nbsp;&nbsp;&nbsp;decimal&nbsp;notation&nbsp;(e.g.,&nbsp;when&nbsp;SCCS&nbsp;is&nbsp;used&nbsp;to&nbsp;maintain&nbsp;the&nbsp;files)&nbsp;<BR>
&nbsp;&nbsp;&nbsp;should&nbsp;beware&nbsp;of&nbsp;a&nbsp;bug&nbsp;in&nbsp;all&nbsp;BIND&nbsp;versions:&nbsp;if&nbsp;the&nbsp;serial&nbsp;number&nbsp;is&nbsp;<BR>
&nbsp;&nbsp;&nbsp;in&nbsp;Release.Version&nbsp;(dotted&nbsp;decimal)&nbsp;notation,&nbsp;then&nbsp;it&nbsp;is&nbsp;virtually&nbsp;<BR>
&nbsp;&nbsp;&nbsp;impossible&nbsp;to&nbsp;change&nbsp;to&nbsp;a&nbsp;higher&nbsp;release:&nbsp;because&nbsp;of&nbsp;the&nbsp;wrong&nbsp;way&nbsp;<BR>
&nbsp;&nbsp;&nbsp;that&nbsp;notation&nbsp;is&nbsp;turned&nbsp;into&nbsp;an&nbsp;integer,&nbsp;it&nbsp;results&nbsp;in&nbsp;a&nbsp;serial&nbsp;<BR>
&nbsp;&nbsp;&nbsp;number&nbsp;that&nbsp;is&nbsp;LOWER&nbsp;than&nbsp;that&nbsp;of&nbsp;the&nbsp;former&nbsp;release.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;For&nbsp;this&nbsp;reason&nbsp;and&nbsp;because&nbsp;the&nbsp;Serial&nbsp;is&nbsp;an&nbsp;(unsigned)&nbsp;integer&nbsp;<BR>
&nbsp;&nbsp;&nbsp;according&nbsp;to&nbsp;STD&nbsp;13,&nbsp;RFC&nbsp;1035,&nbsp;it&nbsp;is&nbsp;recommended&nbsp;not&nbsp;to&nbsp;use&nbsp;the&nbsp;<BR>
&nbsp;&nbsp;&nbsp;dotted&nbsp;decimal&nbsp;notation.&nbsp;A&nbsp;recommended&nbsp;notation&nbsp;is&nbsp;to&nbsp;use&nbsp;the&nbsp;date&nbsp;<BR>
&nbsp;&nbsp;&nbsp;(yyyymmdd),&nbsp;if&nbsp;necessary&nbsp;with&nbsp;an&nbsp;extra&nbsp;digit&nbsp;(yyyymmddn)&nbsp;if&nbsp;there&nbsp;is&nbsp;<BR>
&nbsp;&nbsp;&nbsp;or&nbsp;can&nbsp;be&nbsp;more&nbsp;than&nbsp;one&nbsp;change&nbsp;per&nbsp;day&nbsp;in&nbsp;a&nbsp;zone&nbsp;file.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Very&nbsp;old&nbsp;versions&nbsp;of&nbsp;DNS&nbsp;resolver&nbsp;code&nbsp;have&nbsp;a&nbsp;bug&nbsp;that&nbsp;causes&nbsp;queries&nbsp;<BR>
&nbsp;&nbsp;&nbsp;for&nbsp;A&nbsp;records&nbsp;with&nbsp;domain&nbsp;names&nbsp;like&nbsp;&quot;192.16.184.3&quot;&nbsp;to&nbsp;go&nbsp;out.&nbsp;This&nbsp;<BR>
&nbsp;&nbsp;&nbsp;happens&nbsp;when&nbsp;users&nbsp;type&nbsp;in&nbsp;IP&nbsp;addresses&nbsp;and&nbsp;the&nbsp;resolver&nbsp;code&nbsp;does&nbsp;<BR>
&nbsp;&nbsp;&nbsp;not&nbsp;catch&nbsp;this&nbsp;case&nbsp;before&nbsp;sending&nbsp;out&nbsp;a&nbsp;DNS&nbsp;query.&nbsp;This&nbsp;problem&nbsp;has&nbsp;<BR>
&nbsp;&nbsp;&nbsp;been&nbsp;fixed&nbsp;in&nbsp;all&nbsp;resolver&nbsp;implementations&nbsp;known&nbsp;to&nbsp;us&nbsp;but&nbsp;if&nbsp;it&nbsp;<BR>
&nbsp;&nbsp;&nbsp;still&nbsp;pops&nbsp;up&nbsp;it&nbsp;is&nbsp;very&nbsp;serious&nbsp;because&nbsp;all&nbsp;those&nbsp;queries&nbsp;will&nbsp;go&nbsp;to&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
Beertema&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[Page&nbsp;6]&nbsp;<BR>
&nbsp;<BR>
RFC&nbsp;1537&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Common&nbsp;DNS&nbsp;Data&nbsp;File&nbsp;Configuration&nbsp;Errors&nbsp;&nbsp;&nbsp;&nbsp;October&nbsp;1993&nbsp;<BR>
&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;the&nbsp;root&nbsp;servers&nbsp;looking&nbsp;for&nbsp;top&nbsp;level&nbsp;domains&nbsp;like&nbsp;&quot;3&quot;&nbsp;etc.&nbsp;It&nbsp;is&nbsp;<BR>
&nbsp;&nbsp;&nbsp;strongly&nbsp;recommended&nbsp;to&nbsp;install&nbsp;the&nbsp;latest&nbsp;(publicly)&nbsp;available&nbsp;BIND&nbsp;<BR>
&nbsp;&nbsp;&nbsp;version&nbsp;plus&nbsp;all&nbsp;available&nbsp;patches&nbsp;to&nbsp;get&nbsp;rid&nbsp;of&nbsp;these&nbsp;and&nbsp;other&nbsp;<BR>
&nbsp;&nbsp;&nbsp;problems.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Running&nbsp;secondary&nbsp;nameserver&nbsp;off&nbsp;another&nbsp;secondary&nbsp;nameserver&nbsp;is&nbsp;<BR>
&nbsp;&nbsp;&nbsp;possible,&nbsp;but&nbsp;not&nbsp;recommended&nbsp;unless&nbsp;really&nbsp;necessary:&nbsp;there&nbsp;are&nbsp;<BR>
&nbsp;&nbsp;&nbsp;known&nbsp;cases&nbsp;where&nbsp;it&nbsp;has&nbsp;led&nbsp;to&nbsp;problems&nbsp;like&nbsp;bogus&nbsp;TTL&nbsp;values.&nbsp;This&nbsp;<BR>
&nbsp;&nbsp;&nbsp;can&nbsp;be&nbsp;caused&nbsp;by&nbsp;older&nbsp;or&nbsp;flawed&nbsp;implementations,&nbsp;but&nbsp;secondary&nbsp;<BR>
&nbsp;&nbsp;&nbsp;nameservers&nbsp;in&nbsp;principle&nbsp;should&nbsp;always&nbsp;transfer&nbsp;their&nbsp;zones&nbsp;from&nbsp;the&nbsp;<BR>
&nbsp;&nbsp;&nbsp;official&nbsp;primary&nbsp;nameserver.&nbsp;<BR>
&nbsp;<BR>
11.&nbsp;Some&nbsp;general&nbsp;points&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;The&nbsp;Domain&nbsp;Name&nbsp;System&nbsp;and&nbsp;nameserver&nbsp;are&nbsp;purely&nbsp;technical&nbsp;tools,&nbsp;not&nbsp;<BR>
&nbsp;&nbsp;&nbsp;meant&nbsp;in&nbsp;any&nbsp;way&nbsp;to&nbsp;exert&nbsp;control&nbsp;or&nbsp;impose&nbsp;politics.&nbsp;The&nbsp;function&nbsp;of&nbsp;<BR>
&nbsp;&nbsp;&nbsp;a&nbsp;naming&nbsp;authority&nbsp;is&nbsp;that&nbsp;of&nbsp;a&nbsp;clearing&nbsp;house.&nbsp;Anyone&nbsp;registering&nbsp;a&nbsp;<BR>
&nbsp;&nbsp;&nbsp;subdomain&nbsp;under&nbsp;a&nbsp;particular&nbsp;(top&nbsp;level)&nbsp;domain&nbsp;becomes&nbsp;naming&nbsp;<BR>
&nbsp;&nbsp;&nbsp;authority&nbsp;and&nbsp;therewith&nbsp;the&nbsp;sole&nbsp;responsible&nbsp;for&nbsp;that&nbsp;subdomain.&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Requests&nbsp;to&nbsp;enter&nbsp;MX&nbsp;or&nbsp;NS&nbsp;records&nbsp;concerning&nbsp;such&nbsp;a&nbsp;subdomain&nbsp;<BR>
&nbsp;&nbsp;&nbsp;therefore&nbsp;always&nbsp;MUST&nbsp;be&nbsp;honored&nbsp;by&nbsp;the&nbsp;registrar&nbsp;of&nbsp;the&nbsp;next&nbsp;higher&nbsp;<BR>
&nbsp;&nbsp;&nbsp;domain.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Examples&nbsp;of&nbsp;practices&nbsp;that&nbsp;are&nbsp;not&nbsp;allowed&nbsp;are:&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;-&nbsp;imposing&nbsp;specific&nbsp;mail&nbsp;routing&nbsp;(MX&nbsp;records)&nbsp;when&nbsp;registering&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;subdomain.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;-&nbsp;making&nbsp;registration&nbsp;of&nbsp;a&nbsp;subdomain&nbsp;dependent&nbsp;on&nbsp;to&nbsp;the&nbsp;use&nbsp;of&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;certain&nbsp;networks&nbsp;or&nbsp;services.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;-&nbsp;using&nbsp;TXT&nbsp;records&nbsp;as&nbsp;a&nbsp;means&nbsp;of&nbsp;(free)&nbsp;commercial&nbsp;advertising.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;In&nbsp;the&nbsp;latter&nbsp;case&nbsp;a&nbsp;network&nbsp;service&nbsp;provider&nbsp;could&nbsp;decide&nbsp;to&nbsp;cut&nbsp;off&nbsp;<BR>
&nbsp;&nbsp;&nbsp;a&nbsp;particular&nbsp;site&nbsp;until&nbsp;the&nbsp;offending&nbsp;TXT&nbsp;records&nbsp;have&nbsp;been&nbsp;removed&nbsp;<BR>
&nbsp;&nbsp;&nbsp;from&nbsp;the&nbsp;site's&nbsp;zone&nbsp;file.&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;Of&nbsp;course&nbsp;there&nbsp;are&nbsp;obvious&nbsp;cases&nbsp;where&nbsp;a&nbsp;naming&nbsp;authority&nbsp;can&nbsp;refuse&nbsp;<BR>
&nbsp;&nbsp;&nbsp;to&nbsp;register&nbsp;a&nbsp;particular&nbsp;subdomain&nbsp;and&nbsp;can&nbsp;require&nbsp;a&nbsp;proposed&nbsp;name&nbsp;to&nbsp;<BR>
&nbsp;&nbsp;&nbsp;be&nbsp;changed&nbsp;in&nbsp;order&nbsp;to&nbsp;get&nbsp;it&nbsp;registered&nbsp;(think&nbsp;of&nbsp;DEC&nbsp;trying&nbsp;to&nbsp;<BR>
&nbsp;&nbsp;&nbsp;register&nbsp;a&nbsp;domain&nbsp;IBM.XX).&nbsp;<BR>
&nbsp;<BR>
&nbsp;&nbsp;&nbsp;There&nbsp;are&nbsp;also&nbsp;cases&nbsp;were&nbsp;one&nbsp;has&nbsp;to&nbsp;probe&nbsp;the&nbsp;authority&nbsp;of&nbsp;the&nbsp;<BR>
&nbsp;&nbsp;&nbsp;person:&nbsp;sending&nbsp;in&nbsp;the&nbsp;application&nbsp;-&nbsp;not&nbsp;every&nbsp;systems&nbsp;manager&nbsp;should&nbsp;<BR>