ORA-01031: Insufficient privileges when connecting remotely

In server:

[oracle@local dbs]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Sun Jan 31 19:53:40 2021

Copyright (c) 1982, 2009, Oracle. All rights reserved.

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

When connecting through remotely:

sqlplus sys/oracle123$@target as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Sun Jan 31 20:00:41 2021

Copyright (c) 1982, 2010, Oracle. All rights reserved.

ERROR:

ORA-01031: insufficient privileges

Please help for the above issue..

Note:

1. Tnsping is working fine between two servers.
2. pwd file created with oracle id which was used for software installation.
3.