requested URL /nagios was not found on this server

Hallo,

ich bin heute der Schnellstart-Anleitung (http://nagios.fm4dd.com/docs/de/quickstart-ubuntu.html) für die Installation von Nagios gefolgt. Alles hat soweit eigentlich prima geklappt, so dass ich nun am Punkt "8. Anmelden am Web-Interface" angekommen bin. Das Web-Interface lässt sich leider nicht öffnen: "The requested URL /nagios was not found on this Server."
Apache2 funktioniert allerdings korrekt, wenn ich nur localhost ansteuere. Neustart von Ubuntu und Apache2 hat zu keinem anderen Ergebnis geführt.

/usr/local/nagios/var/nagios.log zeigt mir jetzt direkt auch keine Hinweise:

Zitat

[1442393682] Nagios 4.1.1 starting... (PID=2611)
[1442393682] Local time is Wed Sep 16 10:54:42 CEST 2015
[1442393682] LOG VERSION: 2.0
[1442393682] qh: Socket '/usr/local/nagios/var/rw/nagios.qh' successfully initialized
[1442393682] qh: core query handler registered
[1442393682] nerd: Channel hostchecks registered successfully
[1442393682] nerd: Channel servicechecks registered successfully
[1442393682] nerd: Channel opathchecks registered successfully
[1442393682] nerd: Fully initialized and ready to rock!
[1442393682] wproc: Successfully registered manager as @wproc with query handler
[1442393682] wproc: Registry request: name=Core Worker 2616;pid=2616
[1442393682] wproc: Registry request: name=Core Worker 2615;pid=2615
[1442393682] wproc: Registry request: name=Core Worker 2614;pid=2614
[1442393682] wproc: Registry request: name=Core Worker 2613;pid=2613
[1442393688] Successfully launched command file worker with pid 2618
[1442393907] SERVICE ALERT: localhost;SSH;CRITICAL;SOFT;1;connect to address 127.0.0.1 and port 22: Connection refused
[1442393967] SERVICE ALERT: localhost;SSH;CRITICAL;SOFT;2;connect to address 127.0.0.1 and port 22: Connection refused
[1442394027] SERVICE ALERT: localhost;SSH;CRITICAL;SOFT;3;connect to address 127.0.0.1 and port 22: Connection refused
[1442394087] SERVICE ALERT: localhost;SSH;CRITICAL;HARD;4;connect to address 127.0.0.1 and port 22: Connection refused
[1442397281] Auto-save of retention data completed successfully.
[1442400510] Caught SIGTERM, shutting down...
[1442400510] Caught SIGTERM, shutting down...
[1442400510] Successfully shutdown... (PID=2611)
[1442400510] Event broker module 'NERD' deinitialized successfully.
[1442400523] Nagios 4.1.1 starting... (PID=956)
[1442400523] Local time is Wed Sep 16 12:48:43 CEST 2015
[1442400523] LOG VERSION: 2.0
[1442400523] qh: Socket '/usr/local/nagios/var/rw/nagios.qh' successfully initialized
[1442400523] qh: core query handler registered
[1442400523] nerd: Channel hostchecks registered successfully
[1442400523] nerd: Channel servicechecks registered successfully
[1442400523] nerd: Channel opathchecks registered successfully
[1442400523] nerd: Fully initialized and ready to rock!
[1442400523] wproc: Successfully registered manager as @wproc with query handler
[1442400523] wproc: Registry request: name=Core Worker 959;pid=959
[1442400523] wproc: Registry request: name=Core Worker 960;pid=960
[1442400523] wproc: Registry request: name=Core Worker 961;pid=961
[1442400523] wproc: Registry request: name=Core Worker 958;pid=958
[1442400523] Successfully launched command file worker with pid 965

In /etc/apache2/apache2.conf ist auch kein Alias zu finden bzw. überhaupt das Stichwort nagios. Habt ihr vielleicht irgendein Lösungsvorschlag? Oder sollte ich die Installation nun lieber noch mal von vorne beginnen? Lieben Gruß