Hi everyone,

My router went from IPv4 to IPv6 after an update from my ISP back in April, and so I decided to try and get my selfhosted Raspberry Pi server to work with it. It's been less trivial than I hoped it would be, though. It worked and was reachable when it still used IPv4, but it's been out of the air since April.

I'm running Arch Linux ARM on the device and use networkd to connect it to the internet. I use https://now-dns.com to get a dynamic DNS and have connected it to my server using their Linux script.

This is my Caddyfile:

{
	debug
	
}

# Jellyfin:
https://myserver.now-dns.net:26347,
https://myserver.now-dns.net:443,
[(my IPv6 address here)]:26347 {
	header / {
		# Enable cross-site filter (XSS) 
		# and tell browser to block detected attacks    
		X-Frame-Options "Deny"
		Content-Security-Policy "
	            default-src 'self' data: blob:;
	            style-src 'self' 'unsafe-inline' bootstrapcdn.com *.bootstrapcdn.com https://ctalvio.github.io/Monochromic/default_style.css https://ctalvio.github.io/Monochromic/jfblue_style.css https://ctalvio.github.io/Monochromic/jfpurple_style.css https://ctalvio.github.io/Monochromic/bottom-progress_style.css https://ctalvio.github.io/Monochromic/customcolor-advanced_style.css https://ctalvio.github.io/Monochromic/improve-performance_style.css https://fonts.googleapis.com/css2;
	            script-src 'self' 'unsafe-inline' bootstrapcdn.com *.bootstrapcdn.com googleapis.com *.googleapis.com https://www.gstatic.com/cv/js/sender/v1/cast_sender.js worker-src 'self' blob:;
	            font-src 'self' bootstrapcdn.com *.bootstrapcdn.com;
	            img-src data: 'self' imgur.com *.imgur.com;
	            form-action 'self';
	            connect-src 'self' pokeapi.co;
	            frame-ancestors 'self';
	            report-uri {$CSP_REPORT_URI}
	        "
	}
	reverse_proxy 127.0.0.1:8093
	#reverse_proxy localhost:8093
}

# Nextcloud:
#https://192.168.1.96:65002,
https://myserver.now-dns.net:65001 {
	root * /usr/share/webapps/nextcloud
	file_server
	#        log {
	#                output file     /var/log/caddy/myserver.now-dns.net.log
	#                format single_field common_log
	#        }

	#php_fastcgi 127.0.0.1:9000
	#php_fastcgi unix//run/php-fpm/php-fpm.sock # veranderd naar correcte adres uit /etc/php/php-fpm.d/www.conf
	php_fastcgi unix//run/nextcloud/nextcloud.sock # veranderd naar nieuwe correcte adres uit /etc/php/php-fpm.d/nextcloud.conf

	header {
		# enable HSTS
		Strict-Transport-Security max-age=31536000;
	}

	redir /.well-known/carddav /remote.php/dav 301
	redir /.well-known/caldav /remote.php/dav 301

	# .htaccess / data / config / ... shouldn't be accessible from outside
	@forbidden {
		path /.htaccess
		path /data/*
		path /config/*
		path /db_structure
		path /.xml
		path /README
		path /3rdparty/*
		path /lib/*
		path /templates/*
		path /occ
		path /console.php
	}

	respond @forbidden 404
}

(myserver.now-dns.net is not actually my server name, I changed it to stay a bit more anonymous. Maybe this is unnecessarily cautious, let me know if I should change this to my actual address to aid your help.)

This is a journalctl log from fresh after a Caddy restart:

Aug 01 14:36:12 baspi2 systemd[1]: Starting Caddy web server...
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.0834036,"msg":"using provided configuration","config_file":"/etc/caddy/Caddyfile","config_adapter":""}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"warn","ts":1690893373.0915132,"msg":"No files matching import glob pattern","pattern":"/etc/caddy/conf.d/*"}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.1047359,"logger":"tls.cache.maintenance","msg":"started background certificate maintenance","cache":"0x4394a00"}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.1278725,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv0"}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.1279871,"logger":"http","msg":"server is listening only on the HTTPS port but has no TLS connection policies; adding one to enable TLS","server_name":"srv1","https_port":443}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.1280322,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv1"}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.128112,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv2"}
Aug 01 14:36:13 baspi2 caddy[23895]: {"level":"info","ts":1690893373.1328619,"logger":"tls.cache.maintenance","msg":"stopped background certificate maintenance","cache":"0x4394a00"}
Aug 01 14:36:13 baspi2 caddy[23895]: Valid configuration
Aug 01 14:36:13 baspi2 caddy[23904]: caddy.HomeDir=/var/lib/caddy
Aug 01 14:36:13 baspi2 caddy[23904]: caddy.AppDataDir=/var/lib/caddy
Aug 01 14:36:13 baspi2 caddy[23904]: caddy.AppConfigDir=/etc/caddy
Aug 01 14:36:13 baspi2 caddy[23904]: caddy.ConfigAutosavePath=/var/lib/caddy/autosave.json
Aug 01 14:36:13 baspi2 caddy[23904]: caddy.Version=v2.6.4
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.GOOS=linux
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.GOARCH=arm
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.Compiler=gc
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.NumCPU=4
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.GOMAXPROCS=4
Aug 01 14:36:13 baspi2 caddy[23904]: runtime.Version=go1.20.1
Aug 01 14:36:13 baspi2 caddy[23904]: os.Getwd=/
Aug 01 14:36:13 baspi2 caddy[23904]: LANG=C
Aug 01 14:36:13 baspi2 caddy[23904]: PATH=/usr/local/sbin:/usr/local/bin:/usr/bin
Aug 01 14:36:13 baspi2 caddy[23904]: NOTIFY_SOCKET=/run/systemd/notify
Aug 01 14:36:13 baspi2 caddy[23904]: HOME=/var/lib/caddy
Aug 01 14:36:13 baspi2 caddy[23904]: LOGNAME=caddy
Aug 01 14:36:13 baspi2 caddy[23904]: USER=caddy
Aug 01 14:36:13 baspi2 caddy[23904]: INVOCATION_ID=131202f1b6e3472bab7e6fc48933c731
Aug 01 14:36:13 baspi2 caddy[23904]: JOURNAL_STREAM=8:2593614
Aug 01 14:36:13 baspi2 caddy[23904]: SYSTEMD_EXEC_PID=23904
Aug 01 14:36:13 baspi2 caddy[23904]: XDG_DATA_HOME=/var/lib
Aug 01 14:36:13 baspi2 caddy[23904]: XDG_CONFIG_HOME=/etc
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4270308,"msg":"using provided configuration","config_file":"/etc/caddy/Caddyfile","config_adapter":""}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"warn","ts":1690893373.4276912,"msg":"No files matching import glob pattern","pattern":"/etc/caddy/conf.d/*"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4616253,"logger":"admin","msg":"admin endpoint started","address":"localhost:2019","enforce_origin":false,"origins":["//127.0.0.1:2019","//localhost:2019","//[::1]:2019"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4650905,"logger":"tls.cache.maintenance","msg":"started background certificate maintenance","cache":"0x4e32000"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4871185,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv0"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4872386,"logger":"http","msg":"server is listening only on the HTTPS port but has no TLS connection policies; adding one to enable TLS","server_name":"srv1","https_port":443}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4872835,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv1"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.4874046,"logger":"http","msg":"enabling automatic HTTP->HTTPS redirects","server_name":"srv2"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9077604,"logger":"pki.ca.local","msg":"root certificate is already trusted by system","path":"storage:pki/authorities/local/root.crt"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9084256,"logger":"http","msg":"enabling HTTP/3 listener","addr":":443"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.909473,"logger":"tls","msg":"cleaning storage unit","description":"FileStorage:/var/lib/caddy"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.9139633,"logger":"http","msg":"starting server loop","address":"[::]:443","tls":true,"http3":true}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9140959,"logger":"http.log","msg":"server running","name":"srv1","protocols":["h1","h2","h3"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9144514,"logger":"http","msg":"enabling HTTP/3 listener","addr":":65001"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.91526,"logger":"http","msg":"starting server loop","address":"[::]:65001","tls":true,"http3":true}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9154122,"logger":"http.log","msg":"server running","name":"srv2","protocols":["h1","h2","h3"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.9156892,"logger":"http","msg":"starting server loop","address":"[::]:80","tls":false,"http3":false}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9158008,"logger":"http.log","msg":"server running","name":"remaining_auto_https_redirects","protocols":["h1","h2","h3"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9160817,"logger":"http","msg":"enabling HTTP/3 listener","addr":":26347"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.9165256,"logger":"http","msg":"starting server loop","address":"[::]:26347","tls":true,"http3":true}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.9165914,"logger":"http.log","msg":"server running","name":"srv0","protocols":["h1","h2","h3"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.916624,"logger":"http","msg":"enabling automatic TLS certificate management","domains":["(my IPv6 address here)","myserver.now-dns.net"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"info","ts":1690893373.917206,"logger":"tls","msg":"finished cleaning storage units"}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"warn","ts":1690893373.920347,"logger":"tls","msg":"stapling OCSP","error":"no OCSP stapling for [(my IPv6 address here)]: no OCSP server specified in certificate","identifiers":["(my IPv6 address here)"]}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.920421,"logger":"tls.cache","msg":"added certificate to cache","subjects":["(my IPv6 address here)"],"expiration":1690917213,"managed":true,"issuer_key":"local","hash":"8aa98ab4d6a397ee8784859f4ba69d8df96d6d978247a3436a20cc8373cf9a8a","cache_size":1,"cache_capacity":10000}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.920493,"logger":"events","msg":"event","name":"cached_managed_cert","id":"2420e703-5823-4962-ad5b-05a084aafacb","origin":"tls","data":{"sans":["(my IPv6 address here)"]}}
Aug 01 14:36:13 baspi2 caddy[23904]: {"level":"debug","ts":1690893373.923109,"logger":"tls","msg":"loading managed certificate","domain":"myserver.now-dns.net","expiration":1697974414,"issuer_key":"acme-v02.api.letsencrypt.org-directory","storage":"FileStorage:/var/lib/caddy"}
Aug 01 14:36:14 baspi2 caddy[23904]: {"level":"debug","ts":1690893374.1269143,"logger":"tls.cache","msg":"added certificate to cache","subjects":["myserver.now-dns.net"],"expiration":1697974414,"managed":true,"issuer_key":"acme-v02.api.letsencrypt.org-directory","hash":"7db3c32211ccb2942c5d329650e92ddd63cd9a17670eba2ce29476f3c3e3a741","cache_size":2,"cache_capacity":10000}
Aug 01 14:36:14 baspi2 caddy[23904]: {"level":"debug","ts":1690893374.1271243,"logger":"events","msg":"event","name":"cached_managed_cert","id":"fc000be0-ac06-4ca2-aa53-c14c6fb3ae27","origin":"tls","data":{"sans":["myserver.now-dns.net"]}}
Aug 01 14:36:14 baspi2 caddy[23904]: {"level":"info","ts":1690893374.1345215,"msg":"autosaved config (load with --resume flag)","file":"/var/lib/caddy/autosave.json"}
Aug 01 14:36:14 baspi2 systemd[1]: Started Caddy web server.
Aug 01 14:36:14 baspi2 caddy[23904]: {"level":"info","ts":1690893374.137206,"msg":"serving initial configuration"}
Aug 01 14:36:14 baspi2 sudo[23887]: pam_unix(sudo:session): session closed for user root

• I "opened" the necessary ports on my router (my router calls it that, I realise it's probably more like I unblocked these ports in its IPv6 firewall)
• I scanned the open ports with an IPv6 port scanner (this one) and it shows ports 80 and 443 to be open, as well as ports 65001 and 26347
• I used my public IPv6 address to scan, as well as the myserver.now-dns.net address (which is actually another server name)
• I used a smart phone unconnected to wifi to test, but the site cannot load there, either. I tested from other networks while away from home, too, which also didn't work.

Unfortunately, I still cannot connect to the server with a browser. https://myserver.now-dns.net:26347/ gives an ¨Unable to connect" error on Firefox.

I have been whittling away at this issue on and off since April and haven't really made any big breakthroughs. What would be your first steps in troubleshooting this issue?

When I scan one of the open ports with an online tool, a message like this pops up in the journalctl log:

Aug 01 14:45:49 baspi2 caddy[23904]: {"level":"debug","ts":1690893949.6947021,"logger":"http.stdlib","msg":"http: TLS handshake error from [2a01:4f8:1c1c:2d4e::1]:50079: EOF"}