Rename "hostname" for RP Client

[RPDevelopment]

I read somewhere that a specific hostname may be assigned to a IP address using /etc/hosts, but I only see the ability to change the raspberry hostname. For example, I have a hostname "unknownxxx" appearing in the Admin/Query log that is one of my devices, so, I like to rename it to the name of that device.

[DougieLawson]

The GUI preferences dialog has an option to do this. sudo raspi-config has an option.

[W. H. Heydt]

I read somewhere that a specific hostname may be assigned to a IP address using /etc/hosts, but I only see the ability to change the raspberry hostname. For example, I have a hostname "unknownxxx" appearing in the Admin/Query log that is one of my devices, so, I like to rename it to the name of that device.

Just how would you suggest going about renaming someone else's system? Changing the hostname is done for the system you are doing the changing on.

[rpdom]

Just how would you suggest going about renaming someone else's system?

You can put anything you like in your own /etc/hosts.
For example you could put in this entry in

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8.8.8.8 pingy.pingy.thing

and you would get

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pi@raspberrypi:~ $ ping -c 1 pingy.pingy.thing
PING pingy.pingy.thing (8.8.8.8) 56(84) bytes of data.
64 bytes from pingy.pingy.thing (8.8.8.8): icmp_seq=1 ttl=54 time=18.1 ms

--- pingy.pingy.thing ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 18.067/18.067/18.067/0.000 ms

[RPDevelopment]

(1) I tried the raspi-config and it only provides changing the RP hostname.
(2) I don't understand how to use the editing of Hosts, as suggested.
(3) The hostname I'm attempting to change is a "unknownxxxx" ip hostname. It should be named "abcdevice", since I confirmed it's ip/mac address

[rpdom]

Well, then you put an entry in /etc/hosts on the Pi to say

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1.2.3.4 abcdevice

Replace 1.2.3.4 with the actual IP address of that host. Then whenever you try to access 'abcdevice' on that Pi, it will connect to the correct ip address.

/etc/hosts is a very simple local look-up table. It is only used by the system it is stored on*

*Except when you are running a DNSMasq DNS server on that system, where the entries in that file are propagated to other systems on the same network - but don't worry about that, it's a special case and shouldn't apply here.

[RPDevelopment]

This looks like the solution. As a novice, would you please write the entire code line. Is it sudo /etc/hosts?

[rpdom]

sudo nano /etc/hosts
Just add the new line at the end.

sudo means "run with administrator (root) privileges"
nano is a simple editor
/etc/hosts is the name of the file to edit. You need administrator powers to edit it.

[RPDevelopment]

OK. I'm stupid. "Sudo nano /etc/hosts" yields just the local host listing. Ending the command without the "/" yields a new directory request.

[FTrevorGowen]

OK. I'm stupid. "Sudo nano /etc/hosts" yields just the local host listing. Ending the command without the "/" yields a new directory request.

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sudo nano /etc/hosts

within a terminal should display something like this:

SudoNanoEtcHosts.png (35.1 KiB) Viewed 316 times

The two "lines" at the bottom starting with

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^G Get Help

are nano's keyboard shortcuts (keys + control) and their brief help. It's a very basic, simple editor.
Trev.

[rpdom]

OK. I'm stupid. "Sudo nano /etc/hosts" yields just the local host listing. Ending the command without the "/" yields a new directory request.

Yes. Add the line you need on the end of that file.

[RPDevelopment]

OK. Entering sudo nano /etc/hosts does yield the local host as your insert. However, when you say "add a line", do you mean "sudo nano /etc/hosts/1.2.3.4 newipname" or "sudo nano etc/hosts/1.2.3.4 newipname", with spaces between the IP address and hostname, but no space after the hosts/? I assume that etc is a directory and hosts is a subdirectory

In my earlier progamming days the coding is like "Device name/directory/subdirectory" (c:/photos/family/dogs) then all files in the photos directory/dogs subdirectory would list the file names of all the dog photos. No spaces between directory/subdirectory entries. I assume that we're dealing with a similar format, with all IP addresses and corresponding hostnames are listed, like all IP addresses are listed in the hosts/clients directory. So I would assume sudo nano /etc/hosts IP Address (or HostName), with no space after the "hosts" directory entry.

Then, when finding the desired IP address in the "hosts" directory, I'd edit that IP record to change the current "unknown1212121" with "newipname". I assume the the image would be as you included in your insert, with the 1.2.3.4 IP and "unknown1212121" hostname.

I've tried several iterations, but obviously not correct, sometimes getting "etc" does not exist, or "hosts" does not exist. It's probably a space that's needed, but not entered, or a "/" that's needed, but not entered. I got the "sudo nano /etc/hosts" fine. It's the placement and whether to include spaces or "/" for "added line" that I'm missing. in order to locate the desired IP address for editing. I'm assuming it's a single line command.

Sorry for being such a pain.

[TracyLBaker]

If your pi account allows it without sudo (my pi account doesn't need sudo):

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echo "1.2.3.4 name" >> /etc/hosts

If you're pi account requires sudo:

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echo "1.2.3.4 name" | sudo tee -a /etc/hosts

1.2.3.4 will be IP address of the other system

name will be what you want to call the other system -- this creates an alias for it (it does not change its hostname).

In the first example, >> is a necessity, in the second example, -a is: they both tell the command append to the file instead of overwriting it.

Neither will change an existing entry -- but that's OK. In this scenario, both aliases would work -- you can have (almost) as many as you want per IP.

[rpdom]

As we have said many times, the command to start a simple editor to edit the file that contains your host/ip entries is

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sudo nano /etc/hosts

Typed exactly like that.

That will then show you the file as Trev posted.

You use the arrow keys to move down the screen to after the last line shown (the one that starts with 127.0.1.1).

You may need to press Enter to get a new blank line at the end.

Then you type in the IP address you want to use, then one or more spaces or a tab, then the hostname you want to give that IP address.

Then you press the "o" key while holding the Ctrl key to tell the editor to save the update. It will prompt you with the file name. Press Enter to accept the existing name.

Finally, press "x" while holding down Ctrl to close the editor.

It is that simple.

[RPDevelopment]

Got it! I thought that the adding a line related to extending the sudo command, not in the text editor. Duh! My bad.

I've saved the 8 lines appearing in the text editor after entering the relevant IP Address and proposed hostname change. Now I hope that the PIHole Admin Console shows that changed host name in the query page.

You've been very patient and helpful.

Many thanks.