Add network configuration and DNS settings for various hosts

- Created a new configuration file for ga-al-gw-neu with detailed network interface settings and routing rules.
- Updated existing configurations for ga-al-gw, ga-gh-gw, ga-nh-gw, ga-st-gw-ersatz, ga-st-gw, and ga-st-mail to include additional DNS servers and correct domain controller IPs.
- Disabled systemd-resolved for ga-st-mail to prevent conflicts with DNS settings.
- Added user definitions and SSH key configurations for default users across multiple hosts.

host_vars/ga-st-gw.ga.netz/ga-st-gw-common.yml

@@ -374,8 +374,12 @@ systemd_resolved: true
 #    IPv6: 2001:678:ed0:f000::
 #    Servername für DNS-over-TLS: dot.ffmuc.net
 #    für iOS 14+: DoT-Server-Konfiguration (unsigniert, vom PrHdb)
+# Note: systemd-resolved uses 'FallbackDNS' only if no 'DNS' is configured at all. So
+#       the other (internal) nameserver gateways are listed here as additional DNS servers.
 resolved_nameserver:
   - 127.0.0.1
+  - 192.168.10.1
+  - 192.168.81.1
 
 # search domains
 #
@@ -394,6 +398,7 @@ resolved_dnssec: false
 #
 resolved_fallback_nameserver:
   - 192.168.10.1
+  - 192.168.81.1
 
 
 # ---
@@ -568,7 +573,7 @@ bind9_gateway_acl:
       - '# Nameserver Gateway Stockhausen'
       - 192.168.11.1
       - '# Domain Controller Stockhausen'
-      - 192.168.10.3
+      - 192.168.11.3
       - '# Nameserver Gateway Altenschlirf'
       - 192.168.10.1
       - '# Domain Controller Altenschlirf'
@@ -578,6 +583,8 @@ bind9_gateway_acl:
       - '# Nameserver Gateway Novalishaus'
       - 192.168.81.1
       - 10.2.11.2
+      - '# Nameserver Gateway Georgshaus'
+      - 192.168.85.1
       - '# Nameserver wolle'
       - 10.113.12.3
       - '# Postfix Mailserver'