ORA Error 12637 - Packet receive failed

Toad for Oracle
1

Hi, I am receiving this error only while trying to connect to a database via TOAD.
Can connect via SQL*Plus and SQL Developer.
The recent change was the DB got upgraded from 12.1.1 to 12.1.2. Since then I am unable to connect over VPN. Was able to connect over the VPN prior to upgrade. Yet to try over LAN.
Using TOAD for Oracle 13.0.0.80
Pls advise.

Thank you.

2

Exact same scenario for me. Any insight?

3

There is an issue with configured Firewall (developer is passing while toad is not)
Toad has nothing with this error.