Carlos E. R. wrote:
The Thursday 2008-01-17 at 20:32 +0100, Sandy Drobic wrote:
Does IP now send host names along with the IP address? Any such announcement would have to be application dependent. The name I've
No, unless the developer likes pain, the resolution is the job of the os.
If your box opens a connection to a remote server then the remote server only sees the ip address of your box. The only way to get a hostname for that ip address is to look up the ptr record of that ip from the authoritative dns server responsible for the address space that contains the ip address of your box.
I think there are exceptions, for example in email. Look, from one of mine:
Received: from nimrodel.valinor (88.*.*.*) by ctsmtpout2.frontal.correo (7.2.056.6) (authenticated as ***) id *** for opensuse@opensuse.org; Thu, 17 Jan 2008 16:29:13 +0100
The smtp server of my ISP logs that my machine names itself as nimrodel.valinor, and then logs the real IP
:-)
This is not what will appear in the log of the server. What you see here in the received line is not the dns hostname but your HELO name. (^-^) Postfix for example logs both the hostname AND the HELO name i the received lines to avoid such misunderstandings. (^-^) telnet localhost 25 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 japantest.homelinux.com ESMTP Postfix ehlo bush.must.go! 250-katgartest.washu.lab 250-PIPELINING 250-SIZE 52428800 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN mail from:<testmail@katgartest.washu.lab> 250 2.1.0 Ok rcpt to:<postmaster@katgartest.washu.lab> 250 2.1.5 Ok data 354 End data with <CR><LF>.<CR><LF> . 250 2.0.0 Ok: queued as 0344414F0C quit 221 2.0.0 Bye Connection closed by foreign host. This is the server log of the mail: -------------------------------------------------------- Jan 17 22:25:37 katgartest postfix/smtpd[13883]: connect from localhost[127.0.0.1] Jan 17 22:26:25 katgartest postfix/smtpd[13883]: 1779514F0C: client=localhost[127.0.0.1] Jan 17 22:26:33 katgartest postfix/cleanup[13884]: 1779514F0C: message-id=<20080117212625.1779514F0C@katgartest.washu.lab> Jan 17 22:26:33 katgartest postfix/qmgr[13530]: 1779514F0C: from=<testmail@washu.lab>, size=357, nrcpt=1 (queue active) Jan 17 22:26:35 katgartest postfix/smtpd[13883]: disconnect from localhost[127.0.0.1] -------------------------------------------------------- This is the data part of the mail: -------------------------------------------------------- Received: from bush.must.go! (localhost [127.0.0.1]) by katgartest.washu.lab (Postfix) with ESMTP id 1779514F0C for <postmaster@katgartest.washu.lab>; Thu, 17 Jan 2008 22:26:06 +0100 (CET) -------------------------------------------------------- Now it's pretty clear that this can't be a dns name. (^-^) According to RFC 2821 this SHOULD be a dns name... -- Sandy List replies only please! Please address PMs to: news-reply2 (@) japantest (.) homelinux (.) com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org