Changing port in new install blocks web interface

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1

The issue I am facing:
I'm installing pihole on a new pi because the SD card on my live one seems flaky. I have apache2 in the same pi, and it uses ports :80 and :8080 for other apps.
I want pihole's new web server to render the web interface on :8888 so in
/etc/pihole/pihole.toml I changed
port = "80o,443os,[::]:80o,[::]:443os"
to
port = "8888o,443os,[::]:8888o,[::]:443os"

but when I open http://[newPi-IP]:8888/admin/ I see
Error 404: Not Found
Not found

Opening http://[newPi-IP]:8888/ shows
Error 403: Forbidden
Error: Directory listing denied
which is different to another installation I have that shows a proper 403:
Opening http://[workingPi-IP]:8888/ correctly shows
"403
Oops! Access denied.
You don't have permission to access / on this server.
Did you mean to go to your Pi-hole's dashboard instead?"

So something's different on the new installation.

Details about my system:
It's a freshly installed LAMP server, fully updated after install, RaspiOS bookworm.

I've checked that there's no mention of :8888 in /etc/apache2/ports.conf
which has
Listen 80
Listen 8080
<IfModule etc. ...

and that /etc/apache2/sites-enabled/000-default.conf defines virtual hosts for *:80 and *:8080 only.

What I have changed since installing Pi-hole:
just the port line in /etc/pihole/pihole.toml

2

Please upload a debug log and post just the token URL that is generated after the log is uploaded by running the following command from the Pi-hole host terminal:

pihole -d
3

Thank you.

https://tricorder.pi-hole.net/unH5tcgx/

I have looked through the debug log but can't spot anything that helps me identify the problem.

4

Your debug log shows the web server was successfully started using ports 8888 and 443:

2025-04-23 09:42:57.757 HKT [715M] INFO: Web server ports:
2025-04-23 09:42:57.757 HKT [715M] INFO:   - 0.0.0.0:8888 (HTTP, IPv4, optional, OK)
2025-04-23 09:42:57.757 HKT [715M] INFO:   - 0.0.0.0:443 (HTTPS, IPv4, optional, OK)
2025-04-23 09:42:57.757 HKT [715M] INFO:   - [::]:8888 (HTTP, IPv6, optional, OK)
2025-04-23 09:42:57.758 HKT [715M] INFO:   - [::]:443 (HTTPS, IPv6, optional, OK)

You should be able to access the web interface using: http://192.168.0.110:8888/admin and https://192.168.0.110/admin

This doesn't look like the Pi-hole 404 error.

When you receive the 404 error, do you see a corresponding line in apache2 error log (or maybe in access log)?

5

I just opened http://192.168.0.110:8888/admin/
and find that apache2 access.log for 192.168.0.110 for today is empty (checked with WinSCP and in terminal with nano)

Not until I open http://192.168.0.110:80 does anything appear in the file, as follows:
192.168.0.2 - - [23/Apr/2025:12:08:33 +0800] "GET / HTTP/1.1" 200 3380 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0"
192.168.0.2 - - [23/Apr/2025:12:08:33 +0800] "GET /icons/openlogo-75.png HTTP/1.1" 200 6040 "http://192.168.0.110/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0"

apache2 error.log for today shows
[Wed Apr 23 00:00:11.063908 2025] [mpm_prefork:notice] [pid 866:tid 866] AH00163: Apache/2.4.62 (Debian) configured -- resuming normal operations
[Wed Apr 23 00:00:11.064075 2025] [core:notice] [pid 866:tid 866] AH00094: Command line: '/usr/sbin/apache2'
[Wed Apr 23 00:46:59.460334 2025] [mpm_prefork:notice] [pid 866:tid 866] AH00170: caught SIGWINCH, shutting down gracefully
[Wed Apr 23 09:42:59.107723 2025] [mpm_prefork:notice] [pid 880:tid 880] AH00163: Apache/2.4.62 (Debian) configured -- resuming normal operations
[Wed Apr 23 09:42:59.123946 2025] [core:notice] [pid 880:tid 880] AH00094: Command line: '/usr/sbin/apache2'

I did journalctl -b >journal.txt
Don't really know how to interpret the contents of that but a text search on 'error' showed only lines related to camera and audio that I don't use.

6

I wondered if something else was bound to 8888, so in /etc/pihole/pihole.toml, I changed
port = "8888o,443os,[::]:8888o,[::]:443os"
to
port = "8880o,443os,[::]:8880o,[::]:443os"
but going to http://192.168.0.110:8880/admin/
gave me the same
Error 404: Not Found
Not found

I've now reverted to 8888 (which works on the other pi with a flaky micro SD), but I still have no clue of where else to look. The failure of 8880 to work suggests to me that it's something within the pihole built-in server.

Help!

7

I have now uninstalled pihole completely and then reinstalled it. Changed that one line in pihole.toml to
port = "8888,443os,[::]:80o,[::]:443os" ### CHANGED, default = "80o,443os,[::]:80o,[::]:443os"
making :8888 not optional and leaving IPV6 alone, as I don't use it.

After that, the result is the same.
http://192.168.0.110:8888/admin/
Error 404: Not Found
Not found

Again HELP!

8

I shall start a new question, because I have greatly simplified the setup that reproduces the same problem.

9

Solution identified in a new installation and a new question here: