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Error 1621 
Severity 18 
Message text Type ’%c’ not allowed before login. 
Explanation Adaptive Server uses TDS (Tabular Data Stream) packets to communicate with 
clients. A token is attached to every TDS packet to differentiate between 
different types of packets. During login, Adaptive Server expects a client to 
supply either the TDS_LOGIN or TDS_ECHO token. 
Error 1621 occurs when a client sends a token other than TDS_LOGIN or 
TDS_ECHO at login. Possible causes include: 
• Non-printing characters in the login script. 
• Another process trying to access the port used by the server. 
• An incompatible database driver; for example, an unsupported ODBC 
driver. 
Action To see if other processes are interfering with the port, use netstat (UNIX) or 
Task Manager (NT) and check port status. You can also start the server using a 
different port number to remove any possible interference. 
Check client applications to make sure logins are using a supported database 
driver. On NT, you can use the Drivers tab under ODBC Data Source 
Administrator to see the available drivers. 
Check the TDS login packets being sent to Adaptive Server. To identify the 
affected logins, you can monitor packets: 
• by using trace flags 3605 and 4001 (3605 sends the output to the error log) 
Warning! Use of trace flag 4001 may generate a large number of messages 
in the error log. 
• with the ribo utility (Version 12.0). 
Correct your login scripts to remove non-printing characters or control 
characters, and retry the connection. 
Additional information Refer to “How to Start Adaptive Server with Trace Flags” in Chapter 2 for 
details on using trace flags. 
Version in which this 
error is raised |   
 
 
 
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