Linux Error: 98: Address already in use Listener

If you tried to start listener with srvctl command

$ srvctl start listener -n rac10gn2db1
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 04-JAN-2015 05:20:32
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Copyright (c) 1991, 2010, Oracle.  All rights reserved.
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Starting /u01/app/oracle/product/10.2.0/asm/bin/tnslsnr: please wait...
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:TNSLSNR for Linux: Version 10.2.0.5.0 - Production
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:System parameter file is /u01/app/oracle/product/10.2.0/asm/network/admin/listener.ora
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Log messages written to /u01/app/oracle/product/10.2.0/asm/network/log/listener_rac10gn2db1.log
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.68.1.24)(PORT=1521)))
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac10gn2db1)(PORT=1521)))
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:TNS-12542: TNS:address already in use
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr: TNS-12560: TNS:protocol adapter error
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:  TNS-00512: Address already in use
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:   Linux Error: 98: Address already in use
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Listener failed to start. See the error message(s) above...
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 04-JAN-2015 05:20:33
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Copyright (c) 1991, 2010, Oracle.  All rights reserved.
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac10gn2db1-vip)(PORT=1521)))
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:TNS-12541: TNS:no listener
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr: TNS-12560: TNS:protocol adapter error
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:  TNS-00511: No listener
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:   Linux Error: 111: Connection refused
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac10gn2db1)(PORT=1521)))
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:TNS-12541: TNS:no listener
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr: TNS-12560: TNS:protocol adapter error
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:  TNS-00511: No listener
rac10gn2db1:ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr:   Linux Error: 111: Connection refused
CRS-0215: Could not start resource 'ora.rac10gn2db1.LISTENER_RAC10GN2DB1.lsnr'.

If you start manually if will like following

$ lsnrctl start LISTENER_RAC10GN1DB2

LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 04-JAN-2015 05:34:14

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Starting /u01/app/oracle/product/10.2.0/db/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 10.2.0.5.0 - Production

System parameter file is /u01/app/oracle/product/10.2.0/db/network/admin/listener.ora

Log messages written to /u01/app/oracle/product/10.2.0/db/network/log/listener_rac10gn1db2.log

Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.68.1.26)(PORT=1521)))

Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac10gn1db2)(PORT=1521)))

TNS-12542: TNS:address already in use

 TNS-12560: TNS:protocol adapter error

  TNS-00512: Address already in use

   Linux Error: 98: Address already in use

Listener failed to start. See the error message(s) above...

The issue is because the listener.ora is using hostname instead of IP.

Change all the hostname with the real IP will solve the issue. This applicable for 10g, 11g and non Linux OS as well.