Ken Schneider wrote:

David C. Rankin pecked at the keyboard and wrote:

...

Listmates,

How do you tell ssh to log in as machine x.y.z? With bind running a single machine may be known as:

ftp.domain.com mail.domain.com machinename.domain.com www.domain.com

When using ssh outbound from that box, how do you tell it to ssh as machinename.domain.com and not mail.domain.com?

Thanks.

Would it really matter if all requests go to the same machine/(ip address)?

No, this is just another of my anal retentive moments where I can't understand why my machine wants to ssh out to the world as mail.3111skyline.com. It's another of my inquisitively stupid "Why?" questions. I mean, what logic on the box looks to bind dns and says, "I want to be known as mail today? Hell, why not nemesis.3111skyline.com, it real name? (Ur, Umm, the name of the box is probably at fault) I should have called the son-of-a-bitch accommodating.3111skyline.com and I wouldn't have to put up with this stuff. I know it doesn't matter, but why? -- David C. Rankin, J.D., P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On 17/01/2008, David C. Rankin wrote:

Ken Schneider wrote:

No, this is just another of my anal retentive moments where I can't understand why my machine wants to ssh out to the world as mail.3111skyline.com. It's another of my inquisitively stupid "Why?" questions. I mean, what logic on the box looks to bind dns and says, "I want to be known as mail today? Hell, why not nemesis.3111skyline.com, it real name? (Ur, Umm, the name of the box is probably at fault) I should have called the son-of-a-bitch accommodating.3111skyline.com and I wouldn't have to put up with this stuff.

I know it doesn't matter, but why?

It is simply a problem of incorrectly configured reverse DNS for the domain. A lookup for 66.76.63.120 yields mail.3111skyline.com. If mail and nemesis are on machine as it seems to be I would also consider using CNAME. Regards, -- Marcin Floryan http://marcin.floryan.pl/ Please consider the environment before printing this email. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On 17/01/2008, Sandy Drobic wrote:

...

It is simply a problem of incorrectly configured reverse DNS for the domain. A lookup for 66.76.63.120 yields mail.3111skyline.com. If mail and nemesis are on machine as it seems to be I would also consider using CNAME.

The remote client will log the DNS-Name of the reverse lookup as the client name. How the client announces itself to the world is dependent on the hostname that was configured on the box itself.

The hostname configured on the box does not have to be reflected in what the DNS returns. It is down to the DNS configuration (which in this case is another machine). Sometimes you can get DNS updated by, say DHCP, but I do not think this is the case. It simple the DNS configuration needing to be altered if the reverse DNS lookup result is to be different. Regards, -- Marcin Floryan http://marcin.floryan.pl/ Please consider the environment before printing this email. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

James Knott wrote:

Sandy Drobic wrote:

...

Marcin Floryan wrote:

...

On 17/01/2008, David C. Rankin wrote:

...

Ken Schneider wrote: No, this is just another of my anal retentive moments where I can't understand why my machine wants to ssh out to the world as mail.3111skyline.com. It's another of my inquisitively stupid "Why?" questions. I mean, what logic on the box looks to bind dns and says, "I want to be known as mail today? Hell, why not nemesis.3111skyline.com, it real name? (Ur, Umm, the name of the box is probably at fault) I should have called the son-of-a-bitch accommodating.3111skyline.com and I wouldn't have to put up with this stuff.

I know it doesn't matter, but why? It is simply a problem of incorrectly configured reverse DNS for the domain. A lookup for 66.76.63.120 yields mail.3111skyline.com. If mail and nemesis are on machine as it seems to be I would also consider using CNAME. The remote client will log the DNS-Name of the reverse lookup as the client name. How the client announces itself to the world is dependent on the hostname that was configured on the box itself.

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. If such a ptr record exists, the remote server now has a hostname corresponding to that ip address. In the next step the hostname is verified by looking up this hostname, now the remote server is asking the dns server responsible for the domain of that hostname to find out, what the corresponding ip address for that hostname is. If the hostname exists in dns and points to an ip address, the remote server can now check if the hostname resolves back to the ip address of your box. If that check is successful then the remote server can assume that the hostname is indeed a match for the ip address. There are many ways to foul up this resolution, and ISPs and service providers have found and implemented most of them. :-/ -- 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

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: 250 2.1.0 Ok rcpt to: 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=, 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 ; 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

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

The only rub here is is that my IP is fixed and the ISP manually creates the reverse lookup and adds that to it's reverse zone. In my case they added mail.3111skyline.com as the reverse lookup for the IP 66.76.63.120. Which is fine, but I couldn't explain why all outbound ssh sessions show up as mail.3111skyline.com. Now I know, this thread and the input has lifted the veil of confusion. -- David C. Rankin, J.D., P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

David C. Rankin wrote:

Marcin Floryan wrote:

...

On 17/01/2008, David C. Rankin wrote:

...

Ken Schneider wrote:

...

No, this is just another of my anal retentive moments where I can't understand why my machine wants to ssh out to the world as mail.3111skyline.com. It's another of my inquisitively stupid "Why?" questions. I mean, what logic on the box looks to bind dns and says, "I want to be known as mail today? Hell, why not nemesis.3111skyline.com, it real name? (Ur, Umm, the name of the box is probably at fault) I should have called the son-of-a-bitch accommodating.3111skyline.com and I wouldn't have to put up with this stuff.

I know it doesn't matter, but why?

It is simply a problem of incorrectly configured reverse DNS for the domain. A lookup for 66.76.63.120 yields mail.3111skyline.com. If mail and nemesis are on machine as it seems to be I would also consider using CNAME.

Regards,

Ahah! lightbulb on, it's my upstream dns making the call, but same problem there. My upstream dns is:

3111skyline.com A 66.76.63.120 ftp.3111skyline.com CNAME 3111skyline.com nemesis.3111skyline.com CNAME 3111skyline.com www.3111skyline.com CNAME 3111skyline.com mail.3111skyline.com MX 3111skyline.com - priority: 10

Is it a coin toss for them as well?

No, it's whatever is the default name. As an example, many people have call display, that shows who's calling. When you call someone it shows only the name you provided to the phone company. Now, if someone else uses your phone, will the call display show them? Or you? -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

Marcin Floryan wrote:

On 17/01/2008, David C. Rankin wrote:

...

Ken Schneider wrote:

...

No, this is just another of my anal retentive moments where I can't understand why my machine wants to ssh out to the world as mail.3111skyline.com. It's another of my inquisitively stupid "Why?" questions. I mean, what logic on the box looks to bind dns and says, "I want to be known as mail today? Hell, why not nemesis.3111skyline.com, it real name? (Ur, Umm, the name of the box is probably at fault) I should have called the son-of-a-bitch accommodating.3111skyline.com and I wouldn't have to put up with this stuff.

I know it doesn't matter, but why?

It is simply a problem of incorrectly configured reverse DNS for the domain. A lookup for 66.76.63.120 yields mail.3111skyline.com. If mail and nemesis are on machine as it seems to be I would also consider using CNAME.

Regards,

If there are multiple names pointing to the same IP address, which is the correct one? How is a remote computer to know? For example, I have a host name from my ISP and another name from someone else, both pointing to my IP. If I do a host lookup on my IP address, I get the name from my ISP and not the other one. -- Use OpenOffice.org http://www.openoffice.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

Aaron Kulkis wrote:

David C. Rankin wrote:

...

Listmates,

How do you tell ssh to log in as machine x.y.z? With bind running a single machine may be known as:

ftp.domain.com mail.domain.com machinename.domain.com www.domain.com

When using ssh outbound from that box, how do you tell it to ssh as machinename.domain.com and not mail.domain.com?

wow... that might require /etc/hostfile entries.

DNS is on the same box, and there is an entry in /etc/hosts david@nemesis:~> cat /etc/hosts # # hosts This file describes a number of hostname-to-address # mappings for the TCP/IP subsystem. It is mostly # used at boot time, when no name servers are running. # On small systems, this file can be used instead of a # "named" name server. # Syntax: # # IP-Address Full-Qualified-Hostname Short-Hostname # 127.0.0.1 localhost 192.168.6.20 lakehouse.140shoreline.com lakehouse 192.168.6.16 nemesis.3111skyline.com nemesis -- David C. Rankin, J.D., P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

Ken Schneider wrote:

David C. Rankin pecked at the keyboard and wrote:

...

Aaron Kulkis wrote:

...

David C. Rankin wrote:

...

Listmates,

How do you tell ssh to log in as machine x.y.z? With bind running a single machine may be known as:

ftp.domain.com mail.domain.com machinename.domain.com www.domain.com

When using ssh outbound from that box, how do you tell it to ssh as machinename.domain.com and not mail.domain.com? wow... that might require /etc/hostfile entries.

DNS is on the same box, and there is an entry in /etc/hosts

Doesn't matter unless it also provides DNS to the internet for this box. Otherwise it only supplies info to your local network.

Yes, Ken, I got it, but Aaron seemed a little wrapped around the axle on that one -- kinda surprising. We're all entitled to our _off_ days I guess. -- David C. Rankin, J.D., P.E. Rankin Law Firm, PLLC 510 Ochiltree Street Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org