In this Document

Symptoms

Cause

Solution

---

APPLIES TO:

Oracle Net Services - Version 11.2.0.3 and later  
Information in this document applies to any platform.  

SYMPTOMS

When attempting to tnsping a remote server, 
the following error occurs.

ERROR
-----------------------
 tnsping orcl

TNS Ping Utility for Linux: Version 11.2.0.3.0 - Production on 24-MAY-2013 15:47:42
Copyright (c) 1997, 2011, Oracle.  All rights reserved.
Used parameter files:


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = xx.xx.xx.xx)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl)))
TNS-12543: TNS:destination host unreachable

tnsnames.ora is well configured. lsnrctl status returns normal. orcl instance is registered normally to listener. ping the host succeed

ping xx.xx.xx.xx
PING xx.xx.xx.xx (xx.xx.xx.xx) 56(84) bytes of data.
64 bytes from xx.xx.xx.xx: icmp_seq=1 ttl=63 time=0.671 ms

Strace shows that the tnsping failed with below errors

strace -o a.txt tnsping orcl

$cat a.txt

........

getsockopt(4, SOL_SOCKET, SO_SNDBUF, 0x7fff2b16c0fc, 0x7fff2b16c0f8) = -1 EBADF (Bad file descriptor)
getsockopt(4, SOL_SOCKET, SO_RCVBUF, 0x7fff2b16c0fc, 0x7fff2b16c0f8) = -1 EBADF (Bad file descriptor)
lseek(3, 39936, SEEK_SET)               = 39936
read(3, "\r\0\3650\0\0V\0\3660\0\0t\0\3670\0\0\217\0\3700\0\0\246\0\3710\0\0\277\0"..., 512) = 512
write(1, "TNS-12543: TNS:destination host "..., 44) = 44

 

Also, it is possible that telnet may hang on 1521 port, but is ok on other port

# telnet xx.xx.xx.xx 1521
Trying...
^C# 
# telnet xx.xx.xx.xx 22
Trying...
Connected to xx.xx.xx.xx.

Trying same operation on server locally can succeed.

tnsping orcl

TNS Ping Utility for Linux: Version 11.2.0.3.0 - Production on 27-MAY-2013 15:21:06

Copyright (c) 1997, 2011, Oracle.  All rights reserved.

Used parameter files:
/home/oracle/app/product/11.2.0/dbhome_1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = xx.xx.xx.xx)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl)))
OK (0 msec)

 

CAUSE

This might be a network issue with either the underlying transport not being able to contact the host, or a firewall is blocking this client or connection.

Make sure the network is functioning correctly.

 

 

SOLUTION

Contact OS/network admin to fix the network issue.