I'm running CentOS 7 and have just finished installing Oracle DB 12c. (Installed without configuring)
When I try to create a listener using netca (Oracle Net Configuration Assisstant) this error occurs
Use another port number
The information provided for this port is currently in use by other software on this computer. You can proceed with the configuration as it is, but it will no be possible to start this listener until the conflict is resolved. Would you like to continue with the configuration anyway?
The problem is this error occurs for every other port (I've tried 1522, 9999, 10000, 60000)
I've ignored the error and continued to configure a listener called LISTENER on port 1521 anyway. But dbca fails to start the LISTENER.
Things I've tried
1. I've disabled the firewall
[oracle@prashan bin]$ systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
Active: inactive (dead)
2. I've made sure the the hostname and the /etc/hosts file entries match
[oracle@prashan bin]$ hostname
prashan.pda
[oracle@prashan bin]$ ifconfig
eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.148.131 netmask 255.255.255.0 broadcast 192.168.148.255
inet6 fe80::20c:29ff:fe90:15b8 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:90:15:b8 txqueuelen 1000 (Ethernet)
RX packets 769 bytes 64553 (63.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 230 bytes 22167 (21.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 14 bytes 1176 (1.1 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 14 bytes 1176 (1.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:09:bf:0c txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[oracle@prashan bin]$ cat /etc/hosts
127.0.0.1 prashan.pda
::1 prashan.pda
192.168.148.131 prashan.pda
3. Output of lsnrctl
LSNRCTL> status
Message 1053 not found; No message file for product=network, facility=TNSTNS-12541: Message 12541 not found; No message file for product=network, facility=TNS
TNS-12560: Message 12560 not found; No message file for product=network, facility=TNS
TNS-00511: Message 511 not found; No message file for product=network, facility=TNS
Linux Error: 111: Connection refused
LSNRCTL> start LISTENER
Message 1070 not found; No message file for product=network, facility=TNSTNS-12545: Message 12545 not found; No message file for product=network, facility=TNS
TNS-12560: Message 12560 not found; No message file for product=network, facility=TNS
TNS-00515: Message 515 not found; No message file for product=network, facility=TNS
Linux Error: 2: No such file or directory