# VPN CONFIGURATION FILE ADVISORY
# ===============================

# REVERSE CHRONOLOGY
# ==================
# 2024-04-17: Updated (VPN validity times) ....................... P. Ly, S. Al
# 2024-03-29: Updated ............................................ P. Ly, S. Al
# 2024-01-07: Updated............................................. P. Ly, B. Ho
# 2023-12-12: Updated ..................................... P. Ly, J. Re, B. Ho
# 2021-10-12: Updated ................................................ P. Lynam
# 2021-XX-XX: Early versions .............................. B. Holden, S. Allen

Please be advised:

+ VPN configuration files become valid after 19:00 UT (11:00 AM PST; Noon PDT) 
  on the day for which they are assigned.
  It is NOT advised to attempt early connection on the day for 
  which VPN configuration files have been assigned lest firewalls or 
  system administrators interpret this as a network break-in attempt.

+ Only a limited number of VPN connections can be simultaneously 
  hosted. 

  As of 2024-03-29:

  Known stable: 3 x Nickel+CCD and 1 x Shane+Kast.

  Speculated stable: 4 x Nickel+CCD and 1 x Shane+Kast.

  Pending investigation: Nickel+CCD and Shane+ShaneAO.

+ A single VPN configuration file must be used uniquely for each 
  observer (i.e. in the case of multiple observers observers 
  associated with the same program) more-than-one VPN configuration 
  file may be issued to enable more-than-one observer. 
  In such cases, multiple observers must coordinate among themselves 
  regarding which of the issued VPN configuration files they will 
  use.

+ Depending on the number of sequential nights in the run, VPN 
  configuration files can be valid either for a single night, or 
  for all sequential nights of a run.

+ Occasionally, while a VPN configuration file is in use, but 
  during an idle period (e.g. between afternoon activities and 
  start-of-night operations) a ssh key error may occur.
  This may be provoked by the client system entering a power-
  saving mode.
  This is usually solved by completely stopping the VPN
  connection and all remote operations software and then re-
  starting the VPN and remote software.
  To avoid this, it is recommended that the system should be 
  configured NOT to sleep, NOT to conserve power, and NOT to 
  lock the screen.

+ VPN configuration files become invalid at 19:00 UT on the day 
  following the final night of the run.

+ Please disable and delete VPN configuration files after they 
  expire. Machines attempting to use configuration files 
  continuously for prolonged intervals after expiration resemble 
  an ongoing attack.

+ 2023-12-12: There are some reports of Mac + RealVNC users 
  encountering pop-up error messages of the following form:

     "Invalid endpoint: Port not correctly specified"

  This appears to occur when the vnc name specified has the prefix:
 
     vnc://

  Inspecting the present (2023-12-12) script:

     lick_vnc_launcher.py 

  yields that, for Mac (Darwin) systems, the vnc:// prefix is used.
  By having the prefix set as vnc://, the software would tell the 
  operating system to try to run one VNC instance using the built-in
  client. That may cause two clients to start-up (and conflict).

  Possible solution:

  Observer(s) edit the following file:

     local_config.yaml
 
  Add the following line:

     vncprefix: ''


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