Why can't I monitor localhost connection to PostgresSQL, with Guardium stap, on windows?

Answer

The connection to localhost is done with IPv6 unless you have disabled IPv6.

Guardium don't support IPv6.

To stop Windows from using IPv6 see this article --> 
https://support.microsoft.com/en-us/kb/929852

To see if IPv6 is used. Test like this:

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C:\Program Files\PostgreSQL\9.5\bin>psql -h localhost -U postgres
psql (9.5.0)

postgres=#
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Then, run "netstat -b"

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C:\Program Files\PostgreSQL\9.5\bin>netstat -b

Active Connections

  Proto  Local Address          Foreign Address        State
  TCP    9.68.240.142:3389      argyle:57842           ESTABLISHED
  Dnscache
 [svchost.exe]
  TCP    [::1]:5432             grddb12:53365          ESTABLISHED
 [postgres.exe]
  TCP    [::1]:53365            grddb12:5432           ESTABLISHED
 [psql.exe]

C:\Program Files\PostgreSQL\9.5\bin>
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If you see ::1, then that is a local IPv6 address.

If you specify 127.0.0.1,

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C:\Program Files\PostgreSQL\9.5\bin>psql -h 127.0.0.1 -U postgres
psql (9.5.0)

postgres=#
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You'll find the local IPv4 address (127.0.0.1), and that will be captured ok.

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C:\Program Files\PostgreSQL\9.5\bin>netstat -b

Active Connections

  Proto  Local Address          Foreign Address        State
  TCP    9.68.240.142:3389      argyle:57842           ESTABLISHED
  Dnscache
 [svchost.exe]
  TCP    127.0.0.1:5432         grddb12:53368          ESTABLISHED
 [postgres.exe]
  TCP    127.0.0.1:53368        grddb12:5432           ESTABLISHED
 [psql.exe]

C:\Program Files\PostgreSQL\9.5\bin>
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