Puzzling TNSNAMES problem

I have been facing the following problem in SQLNet and would appreciate any hints:

This is the TCP/IP network setup (Machine/OS - Role)

    UNIXA / HP-UX - Oracle7.3.2.2 DB Server and Applications Client     UNIXB / HP-UX - App. Client

    PC1 / Win95 - App. Client (Server/Network Manager)
    PC2 / Win95 - App. Client
    PC3 / WinNT4.0 - App. Client

A TNSNAMES.ORA has been generated by Network Manager on PC1 and distributed to all machines, using Windows networking on the PCs and FTP from PC1 to the UNIX machines.

Problem:
I can connect to the server in UNIXA from all machines (UNIXA as a client and PCs), except from UNIXB. Connections from UNIXB result in "TNS-3505 Failed to Resolve Name". Using TNSPING in UNIXB results in "TNS-3505". Also, when using the CSM utility in UNIXB (Client Status Monitor) to test the connections from UNIXB to the server, CSM reads the right TNSNAMES.ORA file, correctly lists the services available, and then a "resolve" command results in TNS-3505.

Thoughts:
#1 Not a problem with TNSNAMES fomat, because CSM lists the right services
available in the file.
#2 Not a problem with the ADDRESSES specs in TNSNAMES, because the same
file is being used by all machines, including UNIXA, without any problem.
#3 Not a problem of ASCII vs BINARY FTP to get the file from Network
Manager, because neither one works.
#4 Not a problem of ORACLE environment variables, because TNSPING and CSM
are able to locate TNSNAMES.ORA.

Any suggestions? Thanks in advance

Rogerio Chumbinho Received on Sun Sep 28 1997 - 00:00:00 CDT