PCoIP Zero Client refuses to connect to a View Connection Server

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August 2, 2018

Last modified: 09/03/2023, 6:06 pm

Knowledge Base Article Troubleshooting Session Third Party Enhancements Zero Clients

This is a common issue we run into especially when we depreciate older security components from our firmware. We ran into this issue when we depreciated TLS1.0 and are once again seeing it mow that we have depreciated TLS1.1
The typical message the user will see is "View Connection Server Communication Error". It really does not tell us much other than an error has occurred. Looking in the zero client and the host VM logs may provide additional information for example you mat see a similar error in the zero client log when Enhanced Logging is set to "Session Negotiation". So what does all this mean?

See the two examples below, the first is a failed connection the second is a successful connection.....

Failed connection:
0d,01:13:55.38> LVL:3 RC:   0        MGMT_SYS:CONNECT_PROMPT.PENDING_UI_OR_CMS_PROMPT: transition 129 into CONNECT_PROMPT.VDM_LAUNCH (This is the start of the connection, user hit connect).
0d,01:13:55.38> LVL:2 RC:   0         MGMT_UI:tera_mgmt_ui_set_session_state: STANDALONE
0d,01:13:55.38> LVL:2 RC:   0         MGMT_UI:tera_mgmt_ui_osd_display_main_dialog: CANCEL (OSD screen is disabled and we are starting to set up the session).
0d,01:13:55.38> LVL:2 RC:   0         MGMT_UI:DISCONNECTED: transition 21 into DISCONNECTED (MSG_SESSION_STATE_CHANGED: STANDALONE)
0d,01:13:55.61> LVL:3 RC:   0             MSS:ClientHello sent cipher suite list: 0xc02f 0xc030 0xc027 0xc013 0xc028 0xc014 (these are the supported cipher suites sent from the zero client)
0d,01:13:55.61> LVL:3 RC:   0             MSS:ClientHello sent curve list: 21 23 24 25 
0d,01:13:55.67> LVL:1 RC: -7538      MGMT_SSL:tera_mgmt_ssl_open_connection: SSL_negotiateConnection() failed: (Notice in this case we are getting an error message from the host)
0d,01:13:55.67> LVL:1 RC: -7538      MGMT_SSL:  (-7538) ERR_SSL_FATAL_ALERT
0d,01:13:55.67> LVL:1 RC:-500     MGMT_VDMCSI:tera_mgmt_ssl_open_connection failed (ssl_session_id: 0)
0d,01:13:55.68> LVL:1 RC:-501     MGMT_VDMCSI:tera_mgmt_ssl_close_connection failed (ssl_session_id: 0)
0d,01:13:55.69> LVL:2 RC:   0        MGMT_VDM:View Connection Server communication error.

Successful connection (also notice NTP time is enabled which is VERY important for validating certificates):
2021-10-08T21:32:12.86Z> LVL:3 RC:   0        MGMT_SYS:CONNECT_PROMPT.PENDING_UI_OR_CMS_PROMPT: transition 129 into CONNECT_PROMPT.VDM_LAUNCH
2021-10-08T21:32:12.86Z> LVL:2 RC:   0         MGMT_UI:tera_mgmt_ui_set_session_state: STANDALONE
2021-10-08T21:32:12.86Z> LVL:2 RC:   0         MGMT_UI:tera_mgmt_ui_osd_display_main_dialog: CANCEL
2021-10-08T21:32:12.86Z> LVL:2 RC:   0         MGMT_UI:DISCONNECTED: transition 21 into DISCONNECTED (MSG_SESSION_STATE_CHANGED: STANDALONE)
2021-10-08T21:32:13.09Z> LVL:3 RC:   0             MSS:ClientHello sent cipher suite list: 0xc02f 0xc030 0xc027 0xc013 0xc028 0xc014 
2021-10-08T21:32:13.09Z> LVL:3 RC:   0             MSS:ClientHello sent curve list: 21 23 24 25
2021-10-08T21:32:13.15Z> LVL:3 RC:   0             MSS:ServerHello received cipher suite 0xc02f (notice the successful response from the server)

In the above example the connection was trying to use TLS1.1 to connect, since the firmware being used is 21.07.0 TLS1.1 has been deprecated and when tested with TLS1.2 the connection was successful.

Note:  If having an issue connecting to your View Connection Server running our current firmware and using the latest VMware products this may be related to certificates, cipher suites or TLS version. Please check current release notes for compatibility issues.