Views:

Deep Security will hash the TCP's source or destination IP/port. The hash value will be used to lookup the internal connection table.

The error above appears due to one of these possible reasons:

  • Something is wrong in Deep Security hash function.
  • The hash result is "0".

Thus, there is no firewall or DPI protection in the network connection.

To verify the root cause:

  1. Enable the Deep Security Agent trace debug logs.
  2. Open the trace log.
  3. If you find the log below, it means the hash value is "0". This is a special condition as not every TCP port will have "0" value.

    conn: hash_err: 0

    If there is no such log, it means the hash function is broken.

To resolve the issue, collect and submit the following logs to Trend Micro Technical Support:

Keywords: tcp hash error,hash issue,deep security hash problem