====== Troubleshooting T3C Server connection issues ======
<WRAP round tip 90%>
If //T3C system// was working fine and from some time point it is not working anymore, please verify what changes has been made in network and infrastructure configuration and //Internet// connection in your institution. Often it happens, that after weekend the connection with //T3C Server// is not working due some local infrastructure maintenance.
</WRAP>

===== Assumption =====
  * //T3C Service// and //T3C Console// is running
  * //T3C Console// connection indication in the right section of the status bar shows {{:wiki:connection-noserver.png?15}} icon

===== Possible causes and solutions =====
  * //Internet// connection problem or addresses translation
  * //T3C Server// has a short-term outage or is overloaded
  * //T3C Service// connects to the Internet using a proxy server that is not currently operational or its settings or authorization has changed
  * Communication is blocked by a //Firewall//

==== Internet connection ====
Open an internet browser and try to access multiple sites on the //Internet//. If you have any problems, please contact your ISP or network administrator.

==== Availability of T3C Server ====
Verify the availability of //T3C Server// at https://cs.t3c.sk:
  * The page with the T3C logo in the green circle appears, the connection is OK
  * The page with the T3C logo in the orange circle appears, the server may be temporarily overloaded
  * The page with the T3C logo in the red circle appears or there is no page:
    * Address translation error:
      * In command line run //nslookup//
      * Enter address cs.t3c.sk
      * Verify that it translates to 52.232.111.202
    * The server is blocked - try accessing from another network or other device
    * The server has an outage or the connection is currently overloaded - try it later

==== Proxy server ====
If //T3C Server// is available, but //T3C Service// does not communicate, this may be a problem with proxy servers. Please verify your network settings. See also [[guideserverconnectionproxy|the proxy server setup procedure]].

==== Firewall ====
If //T3C Server// is available, but //T3C Service// does not communicate, network communications may be blocked by a //Firewall//. Try to temporarily disable the //Firewall// and verify connection - in //T3C Console// menu select //View/Update from the T3C Server//.

~~DISCUSSION:off~~