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(Windows) Enable/disable DNS lookup of the Telnet client address.


[Telnet]    DNSLookup=n


This setting enables or disables DNS lookup of the client address in the telnet daemon before passing the address to the Caché process that was created to service the connection. This determines the format of the client address returned by $IO and $ZIO in the Cache process.

The value n may be ON or OFF:

  • When ON (true) a DNS lookup of the client address is performed, and the client name is passed to Caché.

  • When OFF (false), no DNS lookup is performed, and the client address is provided in either dotted decimal format (if the connection was via IPV4) or in the colon separated hexadecimal format (if the connection was via IPV6).

DNS lookup should be disabled if a DNS server is not available to do the lookup, because a long delay will occur during login if the DNS server is not available.

Caché Telnet settings apply only to Windows configurations in which InterSystems supplies the Telnet servers. This parameter is ignored for UNIX® systems.



Range of Values

ON or OFF. The default is ON.

Management Portal

On the page System Administration > Configuration > Device Settings > Telnet Settings, select the Telnet category, In the DNSLookup row, select Edit. Choose ON or OFF.

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