RE: RHEL7 kickstart: how is hostname determined?
"Young, Gregory" <[email protected]> Fri, 4 Oct 2019 14:01:31 +0000
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--===============8475271440494569261== Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_DM5PR11MB160978144B68A61CA031D07D869E0DM5PR11MB1609namp_" --_000_DM5PR11MB160978144B68A61CA031D07D869E0DM5PR11MB1609namp_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I would start by fixing the DHCP on the subdomain subnet. You will want to = send the correct "sub.company.org" for the option 15. Gregory Young From: [email protected] <[email protected]>= On Behalf Of Lee, David (LA Int,RAL,LSCI) Sent: October 4, 2019 4:22 AM To: [email protected] Subject: RHEL7 kickstart: how is hostname determined? All our hosts are registered in an Infoblox DHCP+DNS service as MAC+IP+host= name. We have two one domains and one subdomain. When we kickstart-install a new RHEL7 host on the main domain, it cleanly g= ets its intended hostname from Infoblox/DNS. We can see this very early on= by doing an Alt-F2 and querying the hostname. All is well. But on the subdomain it gets the name "localhost.localdomain" (which seems = to be the "in the absence of anything else" default). A wireshark trace of installations shows a DHCP request and ack. On the ma= in domain this is quickly followed by a DNS PTR query from the host, giving= the host's IP address and successfully returning the host's hostname. By = contrast, on the subdomain, this query is never initiated. (On both domain= s, there are subsequent successful DNS queries of other things as part of t= he ensuing installation, demonstrating that DNS activity is happening.) What might be triggering the hosts on the two different domains to behave d= ifferently, that is, send or not send that DNS/PTR query? Looking deeper into that preceding DHCP request/ACK: The main domain, wher= e all works well, is (for example) "company.org". The subdomain (where thi= s lack of hostname issue arises) is a subdomain, e.g. "sub.company.org". O= ne oddity I spotted, is that the DHCP/ACK returns the same "domain-name" op= tion-15 "company.org" for both. I wonder if that is precipitating a subseq= uent problematical behaviour in that "sub.company.org" context? Any thoughts? Thanks. -- David Lee -- This e-mail and any attachments may contain confidential, copyright and or = privileged material, and are for the use of the intended addressee only. If= you are not the intended addressee or an authorised recipient of the addre= ssee please notify us of receipt by returning the e-mail and do not use, co= py, retain, distribute or disclose the information in or attached to the e-= mail. Any opinions expressed within this e-mail are those of the individual and n= ot necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachme= nts are free from viruses and we cannot accept liability for any damage whi= ch you may sustain as a result of software viruses which may be transmitted= in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England a= nd Wales with its registered office at Diamond House, Harwell Science and I= nnovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom --_000_DM5PR11MB160978144B68A61CA031D07D869E0DM5PR11MB1609namp_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable <html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-micr= osoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" = xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http:= //www.w3.org/TR/REC-html40"> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dus-ascii"= > <meta name=3D"Generator" content=3D"Microsoft Word 15 (filtered medium)"> <style><!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0cm; margin-bottom:.0001pt; font-size:11.0pt; font-family:"Calibri",sans-serif;} a:link, span.MsoHyperlink {mso-style-priority:99; color:#0563C1; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {mso-style-priority:99; color:#954F72; text-decoration:underline;} p.msonormal0, li.msonormal0, div.msonormal0 {mso-style-name:msonormal; margin:0cm; margin-bottom:.0001pt; font-size:11.0pt; font-family:"Calibri",sans-serif;} span.EmailStyle19 {mso-style-type:personal-reply; color:black;} .MsoChpDefault {mso-style-type:export-only; font-size:10.0pt;} @page WordSection1 {size:612.0pt 792.0pt; margin:72.0pt 72.0pt 72.0pt 72.0pt;} div.WordSection1 {page:WordSection1;} --></style><!--[if gte mso 9]><xml> <o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext=3D"edit"> <o:idmap v:ext=3D"edit" data=3D"1" /> </o:shapelayout></xml><![endif]--> </head> <body lang=3D"EN-CA" link=3D"#0563C1" vlink=3D"#954F72"> <div class=3D"WordSection1"> <p class=3D"MsoNormal"><span style=3D"color:black;mso-fareast-language:EN-U= S">I would start by fixing the DHCP on the subdomain subnet. You will want = to send the correct “sub.company.org” for the option 15.<o:p></= o:p></span></p> <p class=3D"MsoNormal"><span style=3D"color:black;mso-fareast-language:EN-U= S"><o:p> </o:p></span></p> <div> <p class=3D"MsoNormal"><b><span lang=3D"EN-US" style=3D"font-size:11.5pt;co= lor:#F99D1C"><o:p> </o:p></span></b></p> <p class=3D"MsoNormal"><b><span lang=3D"EN-US" style=3D"font-size:11.5pt;co= lor:#F99D1C">Gregory Young</span></b><span lang=3D"EN-US" style=3D"font-siz= e:11.5pt;color:#888888"><o:p></o:p></span></p> </div> <p class=3D"MsoNormal"><span style=3D"color:black;mso-fareast-language:EN-U= S"><o:p> </o:p></span></p> <div> <div style=3D"border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm = 0cm 0cm"> <p class=3D"MsoNormal"><b><span lang=3D"EN-US">From:</span></b><span lang= =3D"EN-US"> [email protected] <kickstart-list-bounces@re= dhat.com> <b>On Behalf Of </b>Lee, David (LA Int,RAL,LSCI)<br> <b>Sent:</b> October 4, 2019 4:22 AM<br> <b>To:</b> [email protected]<br> <b>Subject:</b> RHEL7 kickstart: how is hostname determined?<o:p></o:p></sp= an></p> </div> </div> <p class=3D"MsoNormal"><o:p> </o:p></p> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">All our= hosts are registered in an Infoblox DHCP+DNS service as MAC+IP+= ;hostname. We have two one domains and one subdomain.<o:p></o:p></spa= n></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">When we= kickstart-install a new RHEL7 host on the main domain, it cleanly gets its= intended hostname from Infoblox/DNS. We can see this very early on b= y doing an Alt-F2 and querying the hostname. All is well.<o:p></o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">But on = the subdomain it gets the name "localhost.localdomain" (which see= ms to be the "in the absence of anything else" default).<o:p></o:= p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">A wires= hark trace of installations shows a DHCP request and ack. On the main= domain this is quickly followed by a DNS PTR query from the host, giving t= he host's IP address and successfully returning the host's hostname. By contrast, on the subdomain, this query is ne= ver initiated. (On both domains, there are subsequent successful DNS = queries of other things as part of the ensuing installation, demonstrating = that DNS activity is happening.)<o:p></o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">What mi= ght be triggering the hosts on the two different domains to behave differen= tly, that is, send or not send that DNS/PTR query?<o:p></o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">Looking= deeper into that preceding DHCP request/ACK: The main domain, where = all works well, is (for example) "company.org". The subdoma= in (where this lack of hostname issue arises) is a subdomain, e.g. "sub.company.org". One oddity I spotted, is that the = DHCP/ACK returns the same "domain-name" option-15 "company.o= rg" for both. I wonder if that is precipitating a subsequent pro= blematical behaviour in that "sub.company.org" context?<o:p></o:p= ></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">Any tho= ughts? Thanks.<o:p></o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black"><o:p>&n= bsp;</o:p></span></p> </div> <div> <p class=3D"MsoNormal"><span style=3D"font-size:12.0pt;color:black">-- Davi= d Lee<o:p></o:p></span></p> </div> <p> <o:p></o:p></p> <p>-- <o:p></o:p></p> <p>This e-mail and any attachments may contain confidential, copyright and = or privileged material, and are for the use of the intended addressee only.= If you are not the intended addressee or an authorised recipient of the ad= dressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclo= se the information in or attached to the e-mail.<br> Any opinions expressed within this e-mail are those of the individual and n= ot necessarily of Diamond Light Source Ltd. <br> Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachme= nts are free from viruses and we cannot accept liability for any damage whi= ch you may sustain as a result of software viruses which may be transmitted= in or with the message.<br> Diamond Light Source Limited (company no. 4375679). Registered in England a= nd Wales with its registered office at Diamond House, Harwell Science and I= nnovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom<br> <o:p></o:p></p> </div> </body> </html> --_000_DM5PR11MB160978144B68A61CA031D07D869E0DM5PR11MB1609namp_-- --===============8475271440494569261== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Kickstart-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/kickstart-list --===============8475271440494569261==--