12c Client: Approximate 9 - 10 Second Delay in Connecting via Remote SQL*Plus (Doc ID 2218140.1)

Last updated on MARCH 31, 2022

Applies to:

Symptoms

An Oracle 12c client (SQL*Plus) takes approximately 10 seconds to connect to 12c database. 


A review of the client traces shows the connection seemed to hang during the authentication phase.
It also revealed the client was reaching out to the ONS on port 6200:

(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 0F 00 00 00 0F 41 55 54 |.....AUT|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 48 5F 4F 4E 53 5F 43 4F |H_ONS_CO|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 4E 46 49 47 47 00 00 00 |NFIGG...|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 47 6D 61 78 63 6F 6E 6E |Gmaxconn|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 65 63 74 69 6F 6E 73 2E |ections.|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 30 30 30 31 3D 30 30 30 |0001=000|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 33 0A 6E 6F 64 65 73 2E |3.nodes.|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 30 30 30 31 3D 73 73 30 |0001=any|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 30 37 31 31 31 2E 69 6E |host.here|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 74 72 61 30 31 2E 73 61 |.domain.|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 6E 69 74 61 73 2E 63 6F |world.co|
(2724587008) [22-DEC-2016 17:58:03:577] nsbasic_brc: 6D 3A 36 32 30 30 0A 00 |m:6200..|

10 seconds pass when the client abandons the connection to the ONS because:

A) it is not running or
B) it is not reachable through a firewall.

Connection does get established to the database around 10 seconds later:

Note that at 17:58:13 the banner is delivered to the client indicating the connection to the database
is successful:

(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 00 00 00 BE 06 00 00 00 |........|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 00 00 08 A5 00 A5 4F 72 |......Or|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 61 63 6C 65 20 44 61 74 |acle.Dat|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 61 62 61 73 65 20 31 32 |abase.12|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 63 20 45 6E 74 65 72 70 |c.Enterp|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 72 69 73 65 20 45 64 69 |rise.Edi|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 74 69 6F 6E 20 52 65 6C |tion.Rel|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 65 61 73 65 20 31 32 2E |ease.12.|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 31 2E 30 2E 32 2E 30 20 |1.0.2.0.|
(2724587008) [22-DEC-2016 17:58:13:005] nsprecv: 2D 20 36 34 62 69 74 20 |-.64bit.|

Changes

 This is likely a new installation or an upgrade to the 12c client.

Cause

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