Resolve ORA-28545 When trying to access database link between Oracle database and MSSQL

Heterogenous database link between Oracle database and MSSQL was created using the below command.

SQL> create public database link mssql connect to "integration" identified by "*****" using 'dg4msql'; 

Database link created. 

Error Message

SQL> select sysdate from dual@mssql 
2 ; 
select sysdate from dual@mssql 
* 
ERROR at line 1: 
ORA-28545: error diagnosed by Net8 when connecting to an agent 
Unable to retrieve text of NETWORK/NCR message 65535 
ORA-02063: preceding 2 lines from MSSQL 


LISTENER_GTWY = 
(DESCRIPTION_LIST = 
(DESCRIPTION = 
(ADDRESS = (PROTOCOL = TCP)(HOST = oraclegtwy.dmn)(PORT = 1526)) 
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1526)) 
) 
) 
(SID_NAME=dg4msql) 
(ORACLE_HOME=/orabin/gateway_mssql/product/12.1.0/tghome_1) 
(ENV="LD_LIBRARY_PATH=/orabin/gateway_mssql/product/12.1.0/tghome_1/dg4msql/driver/lib:/orabin/gateway_mssql/product/12.1.0/tghome_1/lib") 
(PROGRAM=dg4msql) 


Resolution 
Listener file on the Oracle Database gateway server should look like below 

LISTENER_GTWY = 
(DESCRIPTION_LIST = 
(DESCRIPTION = 
(ADDRESS = (PROTOCOL = TCP)(HOST =oraclegtwy.dmn)(PORT = 1526)) 
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1526)) 
) 
) 

SID_LIST_LISTENER_GTWY =------------------------>Missing 
 (SID_LIST= 
 (SID_DESC= 
 (SID_NAME=dg4msql) 
 (ORACLE_HOME=/orabin/gateway_mssql/product/12.1.0/tghome_1) 
 (ENV="LD_LIBRARY_PATH=/orabin/gateway_mssql/product/12.1.0/tghome_1/dg4msql/driver/lib:/orabin/gateway_mssql/product/12.1.0/tghome_1/lib") 
 (PROGRAM=dg4msql) 
 ) 
 )