Hi Nate,
Apologies for the belated follow-up.
Nate Bargmann writes:
> * On 2019 09 Mar 18:09 -0600, Olaf Meeuwissen wrote:
>> All the info I have seen on this topic in the thread is consistent with
>> hostid returning the "mangled" IP address belonging to the machine's
>> current hostname. This is normally set from /etc/hostname. That file
>> is created during installation. The IP address is in /etc/hosts.
>>
>> Taking 007f0100 as an example, swapping bytes in pairs gives 7f000001
>> which gives 127.0.0.1. For 007f0101 you get 127.0.1.1.
>>
>> I just tried the following on my machine
>>
>> $ sudo hostname yoda # anything different from what you have now
>> $ hostid # this is silent for a while and then says
>> 00000000
>>
>> Presumably, DNS times out and then you get whatever the code used to
>> initialize the return value.
>>
>> Trying to revert my change
>>
>> $ sudo hostname quark # this ponders things for a while and says
>> sudo: unable to resolve host yoda
>> $ hostid
>> 007f0101
>>
>> Please note that the hostname command does *not* modify the contents of
>> /etc/hostname. To persist changes across reboots you'll need to edit
>> /etc/hostname yourself.
>
> It looks like I have an exception:
>
> pi@aprxpi:~$ cat /etc/os-release
> PRETTY_NAME="Raspbian GNU/Linux 8 (jessie)"
> NAME="Raspbian GNU/Linux"
> VERSION_ID="8"
> VERSION="8 (jessie)"
> ID=raspbian
> ID_LIKE=debian
> HOME_URL="http://www.raspbian.org/"
> SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
> BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
> pi@aprxpi:~$ ip address
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> inet 127.0.0.1/8 scope host lo
> valid_lft forever preferred_lft forever
> inet6 ::1/128 scope host
> valid_lft forever preferred_lft forever
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
> link/ether b8:27:eb:8b:f3:1c brd ff:ff:ff:ff:ff:ff
> inet 192.168.25.61/24 brd 192.168.25.255 scope global eth0
> valid_lft forever preferred_lft forever
> inet6 fd5d:beb2:2c86:0:ba27:ebff:fe8b:f31c/64 scope global mngtmpaddr dynamic
> valid_lft forever preferred_lft forever
> inet6 2001:470:1f0f:9fa:ba27:ebff:fe8b:f31c/64 scope global mngtmpaddr dynamic
> valid_lft forever preferred_lft forever
> inet6 fe80::ba27:ebff:fe8b:f31c/64 scope link
> valid_lft forever preferred_lft forever
> 4: ax0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 512 qdisc pfifo_fast state UNKNOWN group default qlen 10
> link/ax25 9c:60:9c:84:40:40:74 brd a2:a6:a8:40:40:40:00
> pi@aprxpi:~$ hostid
> a8c03d19
> pi@aprxpi:~$ hostname
> aprxpi.lan
> pi@aprxpi:~$ cat /etc/hosts
> 127.0.0.1 localhost
> 127.0.1.1 aprxpi
> pi@aprxpi:~$ ll /etc/host*
> -rw-r--r-- 1 root root 9 Aug 7 2006 /etc/host.conf
> -rw-r--r-- 1 root root 11 Mar 11 2018 /etc/hostname
> -rw-r--r-- 1 root root 37 Jun 18 2018 /etc/hosts
> -rw-r--r-- 1 root root 411 Mar 11 2016 /etc/hosts.allow
> -rw-r--r-- 1 root root 711 Mar 11 2016 /etc/hosts.deny
>
>
> On this particular machine the hostid is consistent with the IPv4 address of eth0.
I wrote "the IP address is in /etc/hosts", but I think that should have
been "the IP address what your hostname resolves to" :-/
In many common scenarios that is likely to be the same as what is in
your /etc/hosts file, but really depends on how name resolution is
configured on your machine.
Hope this helps,
--
Olaf Meeuwissen, LPIC-2 FSF Associate Member since 2004-01-27
GnuPG key: F84A2DD9/B3C0 2F47 EA19 64F4 9F13 F43E B8A4 A88A F84A 2DD9
Support Free Software https://my.fsf.org/donate
Join the Free Software Foundation https://my.fsf.org/join
::
Re: [DNG] new freedesktop "standard…
