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Windows: Connections Via the Listener Hang or Error While Local Connections are Successful (Doc ID 466110.1)

Last updated on NOVEMBER 10, 2019

Applies to:

Oracle Net Services - Version and later
Microsoft Windows x64 (64-bit)


Local bequeath connections on the server (e.g. sqlplus system/password) are working fine, but trying to connect via SQL*Net (through the listener) just hangs.

On the server no errors are observed in the listener log or the listener traces.
Oracle Net client and listener trace of failure shows

Handshake and sending connect packet

    nscon: doing connect handshake...
    nscon: sending NSPTCN packet
    nspsend: entry
    nspsend: plen=269, type=1
    nttwr: entry
    nttwr: socket 796 had bytes written=269

And the clientz sits waiting for answer here

    nsprecv: entry
    nsprecv: reading from transport...
    nttrd: entry

Listener trace shows the connect packet arriving

    nscon: doing connect handshake...
    nscon: recving a packet
    nsiooverflow: entry
    nsiooverflow: exit (1)
    nsprecv: entry
    nsprecv: 269 bytes from leftover
    nsprecv: tlen=269, plen=269, type=1
    nsprecv: packet dump

And the handshake

    nsbequeath_stg2: doing connect handshake...
    nsbequeath: doing connect handshake...
    ntpwr: entry

Only server side SQL*Net traces show errors like the following:

nsopen: opening transport...
nserror: nsres: id=0, op=65, ns=12560, ns2=0; nt[0]=0, nt[1]=0, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0
nsopen: unable to open transport
nserror: nsres: id=0, op=73, ns=12560, ns2=0; nt[0]=0, nt[1]=0, nt[2]=0; ora[0]=0, ora[1]=0, ora[2]=0
nsinherit: error exit
nioqper:  error from nsinherit: failed...
nioqper:    ns main err code: 12560
nioqper:    ns (2)  err code: 0
nioqper:    nt main err code: 0
nioqper:    nt (2)  err code: 0
nioqper:    nt OS   err code: 0
niotns: No broken-connection function available.
niomapnserror: entry
niqme: entry
niqme: reporting NS-12560 error as ORA-12560
niqme: exit
niomapnserror: exit
niotns: Couldn't connect, returning 12560



The Listener service has been modified to run under a domain account instead of the default Local System account.  


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