Simple Issue with ORA-00108

My friend asked me to check about error in alert log file - "dispatcher 'D000' encountered error getting listening address". After checked, I found.

Wed Feb 12 09:46:27 2014
dispatcher 'D000' encountered error getting listening address
Wed Feb 12 09:46:27 2014
found dead dispatcher 'D000', pid = (17, 154)

I checked trace file about d000 processed.

Trace file /u01/app/oracle/diag/rdbms/prod/PROD/trace/PROD_d000_31988.trc
Oracle Database 11g Release 11.2.0.1.0 - 64bit Production
ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1
System name:    Linux
Node name:      linux-host
Release:        2.6.39-400.21.1.el6uek.x86_64
Version:        #1 SMP Thu Apr 4 03:49:00 PDT 2013
Machine:        x86_64
Instance name: PROD
Redo thread mounted by this instance: 1
Oracle process number: 17
Unix process pid: 31988, image: oracle@linux-host (D000)


*** 2014-02-12 09:57:35.577
*** CLIENT ID:() 2014-02-12 09:57:35.577
*** SERVICE NAME:() 2014-02-12 09:57:35.577
*** MODULE NAME:() 2014-02-12 09:57:35.577
*** ACTION NAME:() 2014-02-12 09:57:35.577

network error encountered getting listening address:
  NS Primary Error: TNS-12533: TNS:illegal ADDRESS parameters
  NS Secondary Error: TNS-12560: TNS:protocol adapter error
  NT Generic Error: TNS-00503: Illegal ADDRESS parameters
OPIRIP: Uncaught error 108. Error stack:
ORA-00108: failed to set up dispatcher to accept connection asynchronously
(END)

I tried to find out... but no idea... So, checked /etc/hosts

[oracle@linux-host trace]$ cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

[oracle@linux-host trace]$ vi /etc/hosts
[oracle@linux-host trace]$ cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

172.30.6.10     linux-host

Issue was fixed!  Oh! no... I found out on Oracle Support & Internet, but not get solution, but issue was about hostname. - -"