-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-10 09:16, Per Jessen wrote:

Carlos E. R. wrote:

...

Everytime I use YaST to configure the network, it adds this line to /etc/hosts:

127.0.0.2 Telcontar.valinor Telcontar

I have just this weekend installed 12.3 on a xen instance - I get no such line in /etc/hosts. I seem to remember a tickbox with a text along these lines : "write hostname to /etc/hosts" ? (which I never tick).

But I do. I will have to untick.

There is even a FATE related to this: https://features.opensuse.org/308824

Which has been rejected (reason: 11.3 is done). The bugzillas I tried give "access denied" after login. There a dead link to a post at http://fourier.suse.de/mlarch/SuSE/research/2010/research.2010.01/msg00044.h..., server not found. I created a new one. Bug 824141 - appending 127.0.0.2 line to /etc/hosts causes postfix to go berseck

...

What is wrong that postfix does not work with it?

The default value for 'inet_interfaces' is localhost, but you have presumably set it to 'telcontar' or $myhostname ?

inet_interfaces = $myhostname, localhost and localhost last entry in the hosts file is set to ...2, which doesn't work. Well, actually it does, I'm pinging it. But not with postfix. - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG10zAACgkQIvFNjefEBxrDXACeKnmXxX6GKi8+LnwImz9V+96s ifsAoLQFQlgUU7vw/2633IgO4G0QnYJI =1rTb -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-10 16:27, Per Jessen wrote:

Carlos E. R. wrote:

...

...

There is even a FATE related to this: https://features.opensuse.org/308824

Which has been rejected (reason: 11.3 is done). The bugzillas I tried give "access denied" after login.

Sorry, I didn't study the openFATE, my access doesn't work at the moment.

No problem :-) There is one bugzilla at least that was readable, but had just a comment on the end, the main problem was another one, IIRC. I created a new one to track this precise issue on a current and supported release.

That's weird - then 127.0.0.2 is probably assigned to 'lo', so why can't postfix use it.

That ifconfig doesn't print a "lo" for it? - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG149YACgkQIvFNjefEBxpm7gCfeBdcKxUcNby9tok5NVaTCfbv /rwAn2Hxm61bvkBmP6naIFaO+Ui+tPyv =U0n7 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-10 17:48, Per Jessen wrote:

Carlos E. R. wrote:

...

That ifconfig doesn't print a "lo" for it?

127.0.0.0/8 is assigned to 'lo', which is why you can ping it. In order for postfix to use 127.0.0.2 though, I'm sure 'lo' needs 127.0.0.2 added as a secondary address.

It fits... - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG19fUACgkQIvFNjefEBxpxhQCgj7JinFtnLbFruD4d7bvv/cxn CMEAoJ7G8ib/YpEq2w3xSqq2gpP4J2gm =rgvI -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

John Andersen wrote:

On 6/10/2013 8:48 AM, Per Jessen wrote:

...

127.0.0.0/8 is assigned to 'lo', which is why you can ping it. In order for postfix to use 127.0.0.2 though, I'm sure 'lo' needs 127.0.0.2 added as a secondary address.

The problem is that localhost did not appear in hosts, and postfix starts kicking errors for some obscure reason.

Carlos started out by saying he has "127.0.0.1 localhost" in /etc/hosts.

lo gets assigned 127.0.0.1 regardless of the existence of a line in hosts. That you can use anything in 127.0.0.0/8 to ping your own machine doesn't seem germane to the issue here. Its something odd in postfix.

postfix tries to listen on 127.0.0.2, but as that address has not been assigned to any interface, it fails. -- Per Jessen, Zürich (14.1°C) http://www.dns24.ch/ - free DNS hosting, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott wrote:

Per Jessen wrote:

...

postfix tries to listen on 127.0.0.2, but as that address has not been assigned to any interface, it fails.

????

Every usable address in 127.0.0.0 /8 is assigned to lo.

Hmm, yes. But then what is postfix complaining about: "parameter inet_interfaces: no local interface found for 127.0.0.2" inet_interfaces=127.0.0.2 (or similar) will only work if "127.0.0.2" is explicitly assigned to 'lo'. I wonder if postfix is trying to identify the network interface the address is assigned to. -- Per Jessen, Zürich (14.2°C) http://www.dns24.ch/ - free DNS hosting, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

* Carlos E. R. [06-11-13 07:39]:

On 2013-06-11 08:10, Per Jessen wrote:

...

I wonder if postfix is trying to identify the network interface the address is assigned to.

It might. It listens on interfaces, the parameter is named *interfaces...

Have you tried setting inet_interfaces = localhost, 127.0.0.2 or "127.0.0.1, 127.0.0.2" or "all" or "127.0.0/4" re: the last may be incorrect as I am not versed in internet numerology. aiui inet_interfaces defines where postfix should look for incoming mail. another option might be reordering appearance of 127.0.0.1 and 127.0.0.2 in /etc/hosts as the first or last may assume precedence in assignment. I also noticed some great time past the appearance of 127.0.0.2 in "hosts" and wondered w/o resolution it's presence but did not notice any system problems, nor with postfix, so it wasn't important enough to persue. I even have it commented out on one server box.... -- (paka)Patrick Shanahan Plainfield, Indiana, USA HOG # US1244711 http://wahoo.no-ip.org Photo Album: http://wahoo.no-ip.org/gallery2 http://en.opensuse.org openSUSE Community Member Registered Linux User #207535 @ http://linuxcounter.net -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R. wrote:

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1

On 2013-06-11 08:10, Per Jessen wrote:

...

I wonder if postfix is trying to identify the network interface the address is assigned to.

It might. It listens on interfaces, the parameter is named *interfaces...

Normally an application listens on an address and the kernel takes care of the rest. I don't know how I would go about listening on an interface, but tools such as tcpdump know how to. -- Per Jessen, Zürich (19.4°C) http://www.dns24.ch/ - free DNS hosting, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R. wrote:

Carlos E. R.:

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Apararently, my previous reply has been lost. I resend.

On 2013-06-12 14:40, Wietse Venema wrote:

...

Carlos E. R.:

...

Does the machine have a network interface with IP address 127.0.0.2?

Dunno. I guess not, because it is not listed in ifconfig output.

Then, 127.0.0.2 should not be specified in inet_interfaces.

Wietse ····································++-

Thus, I understand they reject this being a postfix problem. This is final, it is an openSUSE problem.

I agree with that - postfix is only doing what it has been told.

YaST should not add that entry to the hosts file;

Or it should make sure it also adds 127.0.0.2 to 'lo'. Which is what used to happen. If that doesn't happen anymore, that is the real problem. -- Per Jessen, Zürich (26.1°C) http://www.dns24.ch/ - free DNS hosting, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

[12.06.2013 20:34] [Carlos E. R.]:

...

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YaST should not add that entry to the hosts file;

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Or it should make sure it also adds 127.0.0.2 to 'lo'. Which is what used to happen. If that doesn't happen anymore, that is the real problem.

All those fine details escape my capabilities :-)

As I just said in bugzilla:

What I would propose is a compromise: as there is a tick box to enable/disable this in YaST network configuration module, that tick box should display a text explaining what it does, and what breaks either way, so that if we get hit by the problems we know where they come from and we don't need to google it ;-)

There is a tickbox in YaST configuration as Per mentioned in the first response in this thread, Message-ID: . In many installation instructions (for example, if you install a SAP system on SLES), you get a direct hint to make sure this box is not ticked. Once you learn that ticking this box writes 127.0.0.2 with your hostname into /etc/hosts, you know that you don't want this feature. AFAIK, the box was unchecked the last times I installed openSUSE (and SLES). At some time, it added 127.0.0.2 to /etc/sysconfig/network/ifcfg-lo too - and this was needed because of some strange rules in CUPS access lists ("allow 127.0.0.2") that were introduced for some obscure reasons. When you look at postfix' config with the line "inet_interfaces = $myhostname, localhost", it is sure meant that $myhostname is resolved to an "outside" address (as opposed to a localhost address). Postfix should check that the given addresses are available for its local installation, though. Maybe one can tell Wietse that this is a security flaw, it will be fixed at once ;-) Just my 2¢, Werner -- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R. [13.06.2013 09:25]:

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When you look at postfix' config with the line "inet_interfaces = $myhostname, localhost", it is sure meant that $myhostname is resolved to an "outside" address (as opposed to a localhost address). Postfix should check that the given addresses are available for its local installation, though. Maybe one can tell Wietse that this is a security flaw, it will be fixed at once ;-)

[..]

As for the $myhostname being an internet address - well, not always. It can be a local network server only, too. For internal exchange only. It just needs a working DNS server.

It can be any address but a localhost address, that's what I meant when I wrote 'it is sure meant that $myhostname is resolved to an "outside" address (as opposed to a localhost address)'. Localhost addresses are in the 127.0.0.0/8 range :-) BTW, everyone using postfix should know the value of a working DNS ;-) Regards, Werner -- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-10 19:14, John Andersen wrote:

On 6/10/2013 8:48 AM, Per Jessen wrote:

...

127.0.0.0/8 is assigned to 'lo', which is why you can ping it. In order for postfix to use 127.0.0.2 though, I'm sure 'lo' needs 127.0.0.2 added as a secondary address.

The problem is that localhost did not appear in hosts, and postfix starts kicking errors for some obscure reason.

localhost is in hosts, twice at least.

lo gets assigned 127.0.0.1 regardless of the existence of a line in hosts.

That you can use anything in 127.0.0.0/8 to ping your own machine doesn't seem germane to the issue here. Its something odd in postfix.

That you can ping that destination is not the same as pinging /from/ that IP. - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG2HJkACgkQIvFNjefEBxpCaQCfQUA+nkm9DPM35pKnQTSOFzkh cEUAoMpGzq6+4gDSLu1BJDy+fv0lARHX =0qmm -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-10 22:10, James Knott wrote:

Carlos E. R. wrote:

...

localhost is in hosts, twice at least.

There's no problem with having more than one line with a host name. Only the first one will be used.

Postfix is attempting to use the last one. My very first line is this: 127.0.0.1 localhost then I have: ::1 localhost ipv6-localhost ipv6-loopback However, postfix is not attempting to use localhost, but "telcontar": 192.168.1.14 Telcontar.valinor Telcontar This is the line that postfix is reading, the very last line of the file: 127.0.0.2 Telcontar.valinor Telcontar and it is created when I run the yast network configuration module (I don't write it). I have a comment written somewhere: # 127.0.0.2 Telcontar.valinor Telcontar --> causes error in postfix. # fatal: parameter inet_interfaces: no local interface found for 127.0.0.2 (one line, Thunderbird forces wrapping the line) It has been happening for years. I have the comment in the hosts file lest I forget. - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG2VXcACgkQIvFNjefEBxqxEQCgl82HZUk+ZwjbPIHSri+APaZl fnwAniLvNdf/HUAqaI1F3Q8AlvhTyY6g =Vciz -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-12 23:13, Bill Cole wrote:

On 10 Jun 2013, at 16:10, James Knott wrote:

...

Carlos E. R. wrote:

...

localhost is in hosts, twice at least.

There's no problem with having more than one line with a host name. Only the first one will be used.

That is not routinely true. Assuming a typical nsswitch.conf, both the traditional gethostbyname() and the modern getaddrinfo() calls that resolve names to addresses both return structures that include all addresses whose entries in /etc/hosts include the name as a value or all values provided by normal DNS resolution of the name, with no particular significance to the ordering of the addresses returned. If (as when setting Postfix's "inet_interfaces" parameter to a list of hostnames) a daemon's configuration tells it to listen on particular addresses by hostname, it is only rational for that daemon to see that as a directive to use all of the addresses to which the name resolves.

That's why this is a problem for Postfix: it is being told to open listeners using a name that resolves to 2 addresses: one that is bound to a configured network interface and 127.0.0.2, which isn't. A quirk of the Linux loopback implementation allows listeners to be opened on any address in 127/8 on the lo interface, but Postfix doesn't (and shouldn't) handle 127/8 specially and open listeners on arbitrary addresses that just happen to work. It sees that 127.0.0.2 isn't configured on any interface, reports its misconfiguration, and dies because that sort of error is severe for a MTA.

Thanks a lot for that detailed explanation :-)

...

The actual address used is the one that's assigned to the interface that is used to reach the destination.

It is common for interfaces to have many more than one IP address assigned to them, so "the one that's assigned to the interface" may be a meaningless phrase. More precisely: a target address uses a particular route which is bound to an interface and may use a specific source address. If you do not specify a source address for ping to use, it will use the source address specific to the route (if their is one) or the default address for the interface to which the route is bound.

Ok, right. I should have said "the ones", then :-) - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG5dQAACgkQtTMYHG2NR9WQpACfbNdTdGuv3vKYAszXUtpszxJ3 5FcAn1VaOJ7fzFqb+4R1KdTo2LOP/Lf1 =jq4q -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2013-06-11 01:35, Felix Miata wrote:

On 2013-06-10 03:16 (GMT-0400) Per Jessen composed:

...

There is even a FATE related to this: https://features.opensuse.org/308824

Since it was rejected,

It was rejected "bureaucratically". The reason given is that it applied to a release, 11.3, that was out, so the fate was too late. Ie, it was left there, nobody doing anything, till it could be closed. I have reopened it, please vote. it may be overdue to reopen the probable reason

it was opened: https://bugzilla.novell.com/show_bug.cgi?id=573488

Yes, they told the guy to open a fate, then they closed the fate and the bugzilla with nothing solved a year later. Nice... - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlG2aOkACgkQIvFNjefEBxrJIACfdU5xI1Gt7DJLrganC+iN3+8R QXkAoLCKAzMyJ1/tPP2i/XBzo3cUn+if =4LzH -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org