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what is the static ip address I assigned to eth0?

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  what is the static ip address I assigned to eth0? rlharris@oplink.net - 2015-08-27 09:10 +0200
    [solved] Re: what is the static ip address I assigned to eth0? rlharris@oplink.net - 2015-08-27 09:30 +0200
      Re: [solved] Re: what is the static ip address I assigned to eth0? Jörg-Volker Peetz <jvpeetz@web.de> - 2015-08-27 12:50 +0200
    Re: what is the static ip address I assigned to eth0? Gene Heskett <gheskett@wdtv.com> - 2015-08-27 10:30 +0200
      Re: what is the static ip address I assigned to eth0? Renaud (Ron) OLGIATI <renaud@olgiati-in-paraguay.org> - 2015-08-27 12:10 +0200
        Re: what is the static ip address I assigned to eth0? Hans <hans.ullrich@loop.de> - 2015-08-27 12:30 +0200
          Re: what is the static ip address I assigned to eth0? David Wright <deblis@lionunicorn.co.uk> - 2015-08-27 20:40 +0200
        Re: what is the static ip address I assigned to eth0? "Thomas Schmitt" <scdbackup@gmx.net> - 2015-08-27 12:30 +0200
        Re: what is the static ip address I assigned to eth0? Gene Heskett <gheskett@wdtv.com> - 2015-08-27 18:10 +0200
    Re: what is the static ip address I assigned to eth0? Elimar Riesebieter <riesebie@lxtec.de> - 2015-08-27 12:00 +0200
      Re: what is the static ip address I assigned to eth0? David Wright <deblis@lionunicorn.co.uk> - 2015-08-27 20:40 +0200
        Re: what is the static ip address I assigned to eth0? Elimar Riesebieter <riesebie@lxtec.de> - 2015-08-28 01:00 +0200
          Re: what is the static ip address I assigned to eth0? David Wright <deblis@lionunicorn.co.uk> - 2015-08-28 06:40 +0200
            Re: what is the static ip address I assigned to eth0? Curt <curty@free.fr> - 2015-08-28 12:10 +0200
              Re: what is the static ip address I assigned to eth0? Brian <ad44@cityscape.co.uk> - 2015-08-28 13:10 +0200
                Re: what is the static ip address I assigned to eth0? Reco <recoverym4n@gmail.com> - 2015-08-28 13:50 +0200
                  Re: what is the static ip address I assigned to eth0? Brian <ad44@cityscape.co.uk> - 2015-08-28 15:40 +0200
                    Re: what is the static ip address I assigned to eth0? Reco <recoverym4n@gmail.com> - 2015-08-28 16:10 +0200
                      Re: what is the static ip address I assigned to eth0? Brian <ad44@cityscape.co.uk> - 2015-08-28 16:50 +0200
                        Re: what is the static ip address I assigned to eth0? Curt <curty@free.fr> - 2015-08-28 18:20 +0200
                          Re: what is the static ip address I assigned to eth0? Brian <ad44@cityscape.co.uk> - 2015-08-28 18:40 +0200
                      Re: what is the static ip address I assigned to eth0? David Wright <deblis@lionunicorn.co.uk> - 2015-08-31 02:10 +0200
                        Re: what is the static ip address I assigned to eth0? Reco <recoverym4n@gmail.com> - 2015-08-31 09:00 +0200
                    Re: what is the static ip address I assigned to eth0? David Wright <deblis@lionunicorn.co.uk> - 2015-08-30 05:10 +0200

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#156860 — what is the static ip address I assigned to eth0?

Months ago I installed Jessie + xfce on a laptop and assigned a static ip
address to eth0.  Now I have forgotten the ip address and need to know it
before I plug it into my local network.

The address is not in /etc/hosts, and there is no Network Manager Applet
in the panel.

How can I determine the address without reinstalling?

rlh

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#156862 — [solved] Re: what is the static ip address I assigned to eth0?

On Thu, August 27, 2015 2:09 am, rlharris@oplink.net wrote:
> Months ago I installed Jessie + xfce on a laptop and assigned a static ip
>  address to eth0.  Now I have forgotten the ip address and need to know
> it before I plug it into my local network.
>
> The address is not in /etc/hosts, and there is no Network Manager Applet
> in the panel.
>
> How can I determine the address without reinstalling?

The solution:  ifconfig

(And it appears that I did not assign a static address, but was using DHCP.)

RLH

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#156878 — Re: [solved] Re: what is the static ip address I assigned to eth0?

Have a look at
https://www.debian.org/doc/manuals/debian-reference/ch05.en.html#_iproute2_commands
as well as the whole chapter 5 of the Debian manual.
The "modern" way to control the IP-address is

$ ip addr

-- 
Regards,
jvp.

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#156866

On Thursday 27 August 2015 03:09:32 rlharris@oplink.net wrote:

> Months ago I installed Jessie + xfce on a laptop and assigned a static
> ip address to eth0.  Now I have forgotten the ip address and need to
> know it before I plug it into my local network.
>
> The address is not in /etc/hosts, and there is no Network Manager
> Applet in the panel.
>
> How can I determine the address without reinstalling?
>
> rlh

Try reading "cat /etc/network/interfaces".  Its a text file.


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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#156873

On Thu, 27 Aug 2015 04:22:11 -0400
Gene Heskett <gheskett@wdtv.com> wrote:

> > Months ago I installed Jessie + xfce on a laptop and assigned a static
> > ip address to eth0.  Now I have forgotten the ip address and need to
> > know it before I plug it into my local network.

> > The address is not in /etc/hosts, and there is no Network Manager
> > Applet in the panel.

> > How can I determine the address without reinstalling?

> Try reading "cat /etc/network/interfaces".  Its a text file.

Or, as root, run

# ifconfig
 
Cheers,
 
Ron.
-- 
           A man will give up almost anything except his suffering.
                                                     -- John Cleese
                                    
                   -- http://www.olgiati-in-paraguay.org --
 

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#156874

Am Donnerstag, 27. August 2015, 12:19:23 schrieb Thomas Schmitt:
Hi,
I understood the question of the op in that way, that he wants to give a new 
ip-address without installing new.

The answer:

You can edit /etc/network/interfaces , after this 
do /etc/init.d/networking restart.

If you are using wicd, just edit the config to your needs, it takes your 
settings before the systems one.

Also you might use network-manager, where you can also edit the settings.

My preferred combination is a combination of /etc/network/interfaces and wicd. 
I tried network-manager, too, but it is IMO not as comfortable as wicd.

Good luck!

Hans

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#156909

Quoting Hans (hans.ullrich@loop.de):
> Am Donnerstag, 27. August 2015, 12:19:23 schrieb Thomas Schmitt:
> Hi,
> I understood the question of the op in that way, that he wants to give a new 
> ip-address without installing new.
> 
> The answer:
> 
> You can edit /etc/network/interfaces , after this 
> do /etc/init.d/networking restart.
> 
> If you are using wicd, just edit the config to your needs, it takes your 
> settings before the systems one.
> 
> Also you might use network-manager, where you can also edit the settings.
> 
> My preferred combination is a combination of /etc/network/interfaces and wicd. 
> I tried network-manager, too, but it is IMO not as comfortable as wicd.

What do you have/need in /etc/network/interfaces except for

# The loopback network interface
auto lo
iface lo inet loopback

I was under the impression that wicd wouldn't manage interfaces listed
in /etc/network/interfaces

Cheers,
David.

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#156875

Hi,

rlharris@oplink.net wrote:
> > The solution:  ifconfig

Renaud (Ron) OLGIATI wrote:
> Or, as root, run

Or as normal user:

  /sbin/ifconfig

It's only a matter of shell PATH, not of permissions.

--------------------------------------------------------

Now why does my eth0 have so many inet6 addr assigned ?
20 pieces of form
  inet6 addr: 2003:.../64 Scope:Global
One of form
  inet6 addr: fe80:.../64 Scope:Link

I am not the only one to wonder. It's a privacy feature
  http://superuser.com/questions/490138/why-do-i-have-so-many-ipv6-inet6-addresses


Have a nice day :)

Thomas

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#156893

On Thursday 27 August 2015 06:02:13 Renaud  OLGIATI wrote:

> On Thu, 27 Aug 2015 04:22:11 -0400
>
> Gene Heskett <gheskett@wdtv.com> wrote:
> > > Months ago I installed Jessie + xfce on a laptop and assigned a
> > > static ip address to eth0.  Now I have forgotten the ip address
> > > and need to know it before I plug it into my local network.
> > >
> > > The address is not in /etc/hosts, and there is no Network Manager
> > > Applet in the panel.
> > >
> > > How can I determine the address without reinstalling?
> >
> > Try reading "cat /etc/network/interfaces".  Its a text file.
>
> Or, as root, run
>
> # ifconfig
>
Which only works if the interface is up and running.  The OP was looking 
for a way to tell the IPV* address before it was running.  And if that 
spec in interfaces is not qualified by the word static, its using dhcp 
and will not be in that file.  OTOH if he is using dhcp, and there is a 
dhcpd running on HIS network, then its a who cares, it just works.  As I 
believe the OP found out later.

> Cheers,
>
> Ron.


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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#156871

* rlharris@oplink.net <rlharris@oplink.net> [2015-08-27 02:09 -0500]:

[...]
> 
> How can I determine the address without reinstalling?

$ host $(hostname)

Elimar
-- 
    .~.
    /V\   L   I   N   U   X
   /( )\ >Phear the Penguin<
   ^^-^^

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#156910

Quoting Elimar Riesebieter (riesebie@lxtec.de):
> * rlharris@oplink.net <rlharris@oplink.net> [2015-08-27 02:09 -0500]:
> 
> [...]
> > 
> > How can I determine the address without reinstalling?
> 
> $ host $(hostname)

$ host junk
Host junk not found: 3(NXDOMAIN)
$

... whether junk is localhost, another PC on the LAN, or indeed "junk".

Cheers,
David.

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#156925

* David Wright <deblis@lionunicorn.co.uk> [2015-08-27 13:29 -0500]:

> Quoting Elimar Riesebieter (riesebie@lxtec.de):
> > * rlharris@oplink.net <rlharris@oplink.net> [2015-08-27 02:09 -0500]:
> > 
> > [...]
> > > 
> > > How can I determine the address without reinstalling?
> > 
> > $ host $(hostname)
> 
> $ host junk
> Host junk not found: 3(NXDOMAIN)
> $
> 
> ... whether junk is localhost, another PC on the LAN, or indeed "junk".

So junk isn't assigned to your LAN's DHCP/DNS server.

Elimar
-- 
 Never make anything simple and efficient when a way
  can be found to make it complex and wonderful ;-)

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#156934

Quoting Elimar Riesebieter (riesebie@lxtec.de):
> * David Wright <deblis@lionunicorn.co.uk> [2015-08-27 13:29 -0500]:
> 
> > Quoting Elimar Riesebieter (riesebie@lxtec.de):
> > > * rlharris@oplink.net <rlharris@oplink.net> [2015-08-27 02:09 -0500]:
> > > 
> > > [...]
> > > > 
> > > > How can I determine the address without reinstalling?
> > > 
> > > $ host $(hostname)

I was trying to ascertain the usefulness of this command in a LAN context.

> > $ host junk
> > Host junk not found: 3(NXDOMAIN)
> > $
> > 
> > ... whether junk is localhost, another PC on the LAN, or indeed "junk".

IOW whatever I substitute for "junk", I get the same reply.

> So junk isn't assigned to your LAN's DHCP/DNS server.

Correct. It's not. I tried putting in the name of this computer,
another (existing) computer and for completion, a non-existent
computer. After all, the message for the latter case might have been
different, which would indicate the command was doing *something* even
if it wasn't particularly useful.

Or, to spell it out:

$ host localhost
Host localhost not found: 3(NXDOMAIN)
$ ping localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
[...]
$ host alum
Host alum not found: 3(NXDOMAIN)
$ ping alum
PING alum (127.0.1.1) 56(84) bytes of data.
64 bytes from alum (127.0.1.1): icmp_req=1 ttl=64 time=0.036 ms
[...]
$ host west
Host west not found: 3(NXDOMAIN)
$ ping west
PING west (192.168.1.15) 56(84) bytes of data.
64 bytes from west (192.168.1.15): icmp_req=1 ttl=64 time=5.61 ms
[...]
$ host junk
Host junk not found: 3(NXDOMAIN)
$ ping junk
ping: unknown host junk
$ 

and from west:

$ host alum
Host alum not found: 3(NXDOMAIN)
$ ping alum
PING alum (192.168.1.19) 56(84) bytes of data.
64 bytes from alum (192.168.1.19): icmp_seq=1 ttl=64 time=5.30 ms
[...]
$ 

But just to show that I really do exist:

$ host www.google.com
www.google.com has address 173.194.115.18
www.google.com has address 173.194.115.20
www.google.com has address 173.194.115.16
www.google.com has address 173.194.115.19
www.google.com has address 173.194.115.17
www.google.com has IPv6 address 2607:f8b0:4000:806::1012
$ 

Cheers,
David.

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#156946

On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
>
> $ host localhost
> Host localhost not found: 3(NXDOMAIN)
> $ ping localhost
> PING localhost (127.0.0.1) 56(84) bytes of data.
> 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms

curty@einstein:~$ host localhost
localhost has address 127.0.0.1
localhost has IPv6 address ::1

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#156948

On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote:

> On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
> >
> > $ host localhost
> > Host localhost not found: 3(NXDOMAIN)
> > $ ping localhost
> > PING localhost (127.0.0.1) 56(84) bytes of data.
> > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
> 
> curty@einstein:~$ host localhost
> localhost has address 127.0.0.1
> localhost has IPv6 address ::1

To complete the picture:

  brian@desktop:~$ dig -x 127.0.0.1

  ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7146
  ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 4096
  ;; QUESTION SECTION:
  ;1.0.0.127.in-addr.arpa.                IN      PTR

  ;; ANSWER SECTION:
  1.0.0.127.in-addr.arpa. 10800   IN      PTR     localhost.

  ;; Query time: 24 msec
  ;; SERVER: 158.152.1.43#53(158.152.1.43)
  ;; WHEN: Fri Aug 28 12:03:15 BST 2015
  ;; MSG SIZE  rcvd: 74

host and dig use only the DNS.

Elimar's suggestion to use 'host $(hostname)' will work if hostname is
a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system.

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#156949

 Hi.

On Fri, 28 Aug 2015 12:09:08 +0100
Brian <ad44@cityscape.co.uk> wrote:

> On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote:
> 
> > On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
> > >
> > > $ host localhost
> > > Host localhost not found: 3(NXDOMAIN)
> > > $ ping localhost
> > > PING localhost (127.0.0.1) 56(84) bytes of data.
> > > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
> > 
> > curty@einstein:~$ host localhost
> > localhost has address 127.0.0.1
> > localhost has IPv6 address ::1
> 
> To complete the picture:
> 
>   brian@desktop:~$ dig -x 127.0.0.1
> 
>   ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1
>   ;; global options: +cmd
>   ;; Got answer:
>   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7146
>   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> 
>   ;; OPT PSEUDOSECTION:
>   ; EDNS: version: 0, flags:; udp: 4096
>   ;; QUESTION SECTION:
>   ;1.0.0.127.in-addr.arpa.                IN      PTR
> 
>   ;; ANSWER SECTION:
>   1.0.0.127.in-addr.arpa. 10800   IN      PTR     localhost.
> 
>   ;; Query time: 24 msec
>   ;; SERVER: 158.152.1.43#53(158.152.1.43)
>   ;; WHEN: Fri Aug 28 12:03:15 BST 2015
>   ;; MSG SIZE  rcvd: 74
> 
> host and dig use only the DNS.
> 
> Elimar's suggestion to use 'host $(hostname)' will work if hostname is
> a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system.

Not unless said 'stock Debian system' has 'search <domain>' stanza
in /etc/resolv.conf.

Reco

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#156964

On Fri 28 Aug 2015 at 14:45:32 +0300, Reco wrote:

>  Hi.
> 
> On Fri, 28 Aug 2015 12:09:08 +0100
> Brian <ad44@cityscape.co.uk> wrote:
> 
> > On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote:
> > 
> > > On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
> > > >
> > > > $ host localhost
> > > > Host localhost not found: 3(NXDOMAIN)
> > > > $ ping localhost
> > > > PING localhost (127.0.0.1) 56(84) bytes of data.
> > > > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
> > > 
> > > curty@einstein:~$ host localhost
> > > localhost has address 127.0.0.1
> > > localhost has IPv6 address ::1
> > 
> > To complete the picture:
> > 
> >   brian@desktop:~$ dig -x 127.0.0.1
> > 
> >   ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1
> >   ;; global options: +cmd
> >   ;; Got answer:
> >   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7146
> >   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> > 
> >   ;; OPT PSEUDOSECTION:
> >   ; EDNS: version: 0, flags:; udp: 4096
> >   ;; QUESTION SECTION:
> >   ;1.0.0.127.in-addr.arpa.                IN      PTR
> > 
> >   ;; ANSWER SECTION:
> >   1.0.0.127.in-addr.arpa. 10800   IN      PTR     localhost.
> > 
> >   ;; Query time: 24 msec
> >   ;; SERVER: 158.152.1.43#53(158.152.1.43)
> >   ;; WHEN: Fri Aug 28 12:03:15 BST 2015
> >   ;; MSG SIZE  rcvd: 74
> > 
> > host and dig use only the DNS.
> > 
> > Elimar's suggestion to use 'host $(hostname)' will work if hostname is
> > a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system.
> 
> Not unless said 'stock Debian system' has 'search <domain>' stanza
> in /etc/resolv.conf.

Does "search example.org" count? :)

What is not understandable (to me) is why 'host localhost' resolves for
some but not for others and why it is thought 'host $(hostname)' should
resolve in the DNS.

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#156967

 Hi.

On Fri, 28 Aug 2015 14:35:09 +0100
Brian <ad44@cityscape.co.uk> wrote:

> On Fri 28 Aug 2015 at 14:45:32 +0300, Reco wrote:
> 
> >  Hi.
> > 
> > On Fri, 28 Aug 2015 12:09:08 +0100
> > Brian <ad44@cityscape.co.uk> wrote:
> > 
> > > On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote:
> > > 
> > > > On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
> > > > >
> > > > > $ host localhost
> > > > > Host localhost not found: 3(NXDOMAIN)
> > > > > $ ping localhost
> > > > > PING localhost (127.0.0.1) 56(84) bytes of data.
> > > > > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
> > > > 
> > > > curty@einstein:~$ host localhost
> > > > localhost has address 127.0.0.1
> > > > localhost has IPv6 address ::1
> > > 
> > > To complete the picture:
> > > 
> > >   brian@desktop:~$ dig -x 127.0.0.1
> > > 
> > >   ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1
> > >   ;; global options: +cmd
> > >   ;; Got answer:
> > >   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7146
> > >   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> > > 
> > >   ;; OPT PSEUDOSECTION:
> > >   ; EDNS: version: 0, flags:; udp: 4096
> > >   ;; QUESTION SECTION:
> > >   ;1.0.0.127.in-addr.arpa.                IN      PTR
> > > 
> > >   ;; ANSWER SECTION:
> > >   1.0.0.127.in-addr.arpa. 10800   IN      PTR     localhost.
> > > 
> > >   ;; Query time: 24 msec
> > >   ;; SERVER: 158.152.1.43#53(158.152.1.43)
> > >   ;; WHEN: Fri Aug 28 12:03:15 BST 2015
> > >   ;; MSG SIZE  rcvd: 74
> > > 
> > > host and dig use only the DNS.
> > > 
> > > Elimar's suggestion to use 'host $(hostname)' will work if hostname is
> > > a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system.
> > 
> > Not unless said 'stock Debian system' has 'search <domain>' stanza
> > in /etc/resolv.conf.
> 
> Does "search example.org" count? :)

It should count for the hosts in this domain. Provided, of course, that
one needs to resolve 'bare' hostnames (i.e. non-FQDN).

 
> What is not understandable (to me) is why 'host localhost' resolves for
> some but not for others and why it is thought 'host $(hostname)' should
> resolve in the DNS.

Stock Debian BIND configuration includes this wonderful snippet
(/etc/bind/db.local):

;
; BIND data file for local loopback interface
;
$TTL    604800
@       IN      SOA     localhost. root.localhost. (
                              2         ; Serial
                         604800         ; Refresh
                          86400         ; Retry
                        2419200         ; Expire
                         604800 )       ; Negative Cache TTL
;
@       IN      NS      localhost.
@       IN      A       127.0.0.1
@       IN      AAAA    ::1

Translating this to English - every BIND installed on Debian considers
itself the final authority on "localhost" zone and always returns
127.0.0.1 for A queries (IPv4) and ::1 for AAAA queries (IPv6).
Other Linux distributions can store zone files elsewhere, but the
principle is the same.
Interpreting /etc/bind/db.127 (PTR entries) is left for an exercise for
the readers.


So - 'host localhost' *should* work given an ideal world (because in
ideal world everyone will use an ideal DNS, which is BIND). But:

a) There are other DNSes. Some of them even may be configured in a sane
way, if you're lucky. In the case of doubt - use 'dig' or 'tcpdump'.

b) There's endless amount of quirks in client resolvers. In layman
terms - 'which part of "search" should I append to the bare hostname'.
In the case of doubt - use 'tcpdump'.

Reco

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#156973

On Fri 28 Aug 2015 at 17:00:59 +0300, Reco wrote:

>  Hi.
> 
> On Fri, 28 Aug 2015 14:35:09 +0100
> Brian <ad44@cityscape.co.uk> wrote:
> 
> > On Fri 28 Aug 2015 at 14:45:32 +0300, Reco wrote:
> > 
> > >  Hi.
> > > 
> > > On Fri, 28 Aug 2015 12:09:08 +0100
> > > Brian <ad44@cityscape.co.uk> wrote:
> > > 
> > > > On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote:
> > > > 
> > > > > On 2015-08-28, David Wright <deblis@lionunicorn.co.uk> wrote:
> > > > > >
> > > > > > $ host localhost
> > > > > > Host localhost not found: 3(NXDOMAIN)
> > > > > > $ ping localhost
> > > > > > PING localhost (127.0.0.1) 56(84) bytes of data.
> > > > > > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms
> > > > > 
> > > > > curty@einstein:~$ host localhost
> > > > > localhost has address 127.0.0.1
> > > > > localhost has IPv6 address ::1
> > > > 
> > > > To complete the picture:
> > > > 
> > > >   brian@desktop:~$ dig -x 127.0.0.1
> > > > 
> > > >   ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1
> > > >   ;; global options: +cmd
> > > >   ;; Got answer:
> > > >   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7146
> > > >   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
> > > > 
> > > >   ;; OPT PSEUDOSECTION:
> > > >   ; EDNS: version: 0, flags:; udp: 4096
> > > >   ;; QUESTION SECTION:
> > > >   ;1.0.0.127.in-addr.arpa.                IN      PTR
> > > > 
> > > >   ;; ANSWER SECTION:
> > > >   1.0.0.127.in-addr.arpa. 10800   IN      PTR     localhost.
> > > > 
> > > >   ;; Query time: 24 msec
> > > >   ;; SERVER: 158.152.1.43#53(158.152.1.43)
> > > >   ;; WHEN: Fri Aug 28 12:03:15 BST 2015
> > > >   ;; MSG SIZE  rcvd: 74
> > > > 
> > > > host and dig use only the DNS.
> > > > 
> > > > Elimar's suggestion to use 'host $(hostname)' will work if hostname is
> > > > a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system.
> > > 
> > > Not unless said 'stock Debian system' has 'search <domain>' stanza
> > > in /etc/resolv.conf.
> > 
> > Does "search example.org" count? :)
> 
> It should count for the hosts in this domain. Provided, of course, that
> one needs to resolve 'bare' hostnames (i.e. non-FQDN).
> 
>  
> > What is not understandable (to me) is why 'host localhost' resolves for
> > some but not for others and why it is thought 'host $(hostname)' should
> > resolve in the DNS.
> 
> Stock Debian BIND configuration includes this wonderful snippet
> (/etc/bind/db.local):
> 
> ;
> ; BIND data file for local loopback interface
> ;
> $TTL    604800
> @       IN      SOA     localhost. root.localhost. (
>                               2         ; Serial
>                          604800         ; Refresh
>                           86400         ; Retry
>                         2419200         ; Expire
>                          604800 )       ; Negative Cache TTL
> ;
> @       IN      NS      localhost.
> @       IN      A       127.0.0.1
> @       IN      AAAA    ::1
> 
> Translating this to English - every BIND installed on Debian considers
> itself the final authority on "localhost" zone and always returns
> 127.0.0.1 for A queries (IPv4) and ::1 for AAAA queries (IPv6).
> Other Linux distributions can store zone files elsewhere, but the
> principle is the same.
> Interpreting /etc/bind/db.127 (PTR entries) is left for an exercise for
> the readers.
> 
> 
> So - 'host localhost' *should* work given an ideal world (because in
> ideal world everyone will use an ideal DNS, which is BIND). But:
> 
> a) There are other DNSes. Some of them even may be configured in a sane
> way, if you're lucky. In the case of doubt - use 'dig' or 'tcpdump'.
> 
> b) There's endless amount of quirks in client resolvers. In layman
> terms - 'which part of "search" should I append to the bare hostname'.
> In the case of doubt - use 'tcpdump'.

Thanks for the nice explanation. It lead me to RFC 6761

  https://tools.ietf.org/html/rfc6761

There it says:

  Name resolution APIs and libraries SHOULD recognize localhost
  names as special and SHOULD always return the IP loopback address
  for address queries and negative responses for all other query
  types.  Name resolution APIs SHOULD NOT send queries for
  localhost names to their configured caching DNS server(s).

I think I'll leave this topic at this point before I get in over my
head, but the implication here is that a resolver not giving 127.0.0.1
for localhost is broken in some way.

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#156988

On 2015-08-28, Brian <ad44@cityscape.co.uk> wrote:
>
> I think I'll leave this topic at this point before I get in over my
> head, but the implication here is that a resolver not giving 127.0.0.1
> for localhost is broken in some way.
>

So I'm not broken somehow.

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