So I completed I new instalation. Now I run on debian with basic installation. No desktop, no firewall.
So I had some problème to start all previous container (swag and other services) because it seems an Alpine linux only use port 53/udp for some application, like curl. and my swag needed to update a mod to be able to install my certbot version. I resolved this issue with a custon swag build BUT the real problem is my ISP bloc 53/udp, not TCP.
I validate that with dig cmd on my host and on the undound container. dig +tcp work fine, not dig (+udp).
UDP:
# dig fuzzy.mailcow.email
;; communications error to 127.0.0.11#53: timed out
;; communications error to 127.0.0.11#53: timed out
;; communications error to 127.0.0.11#53: timed out
; <<>> DiG 9.18.34 <<>> fuzzy.mailcow.email
;; global options: +cmd
;; no servers could be reached
TCP:
/ # dig +tcp fuzzy.mailcow.email
; <<>> DiG 9.18.34 <<>> +tcp fuzzy.mailcow.email
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31744
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;fuzzy.mailcow.email. IN A
;; ANSWER SECTION:
fuzzy.mailcow.email. 62077 IN A 178.156.167.240
;; Query time: 11 msec
;; SERVER: 127.0.0.11#53(127.0.0.11) (TCP)
;; WHEN: Fri Feb 06 10:20:58 EST 2026
;; MSG SIZE rcvd: 64
I tried with other DNS server (1.1.1.1, 8.8.8.8, etc) same behaviour.
I added Options use-vc on the resolv.conf. It`s work for my host but not in container.
/ # cat /etc/resolv.conf
# Generated by Docker Engine.
# This file can be edited; Docker Engine will not make further changes once it
# has been modified.
nameserver 127.0.0.11
options use-vc ndots:0
# Based on host file: '/etc/resolv.conf' (internal resolver)
# ExtServers: [1.1.1.1 8.8.8.8 9.9.9.9]
# Overrides: [nameservers options]
# Option ndots from: internal
On unbound.conf I saw do-udp: yes and I tried to put it to no but no effect.
So if you have any idea I will listen them.