Host name syntax

Note: This special syntax is generally not used from the user interfaces of wc3270 or wx3270, except in scripts or at the x3270&gt; prompt. Those user interfaces allow these options to be specified separately, and construct a properly-formatted host name from them.

Basic syntax
The basic syntax is:


 * [prefix:...] host [:port] [=accept-name]

Prefixes
A prefix sets an option for a single host session, rather than for all sessions created by the emulator. A prefix is a single letter, separated from the host name by a colon (:), e.g.: L:host.foo.com To specify multiple prefixes, separate each of them with a colon, e.g.: L:Y:host.foo.com


 * A - NVT-only session
 * Marks the host as supporting NVT mode only. The emulator does not attempt to negotiate 3270 mode, and defaults the terminal name to  (if a monochrome display) or   (if a color display, New in 4.2 ).


 * B - No-op
 * Formerly caused a change in bind-unlock behavior, but this has now been subsumed by the default value of the bindUnlock resource.


 * C - CICS host
 * Disables the automatic keyboard lock after connecting to a host, waiting for the host to format the screen. This is needed for CICS hosts, for example, which do not initially format the screen.


 * L - Use a TLS tunnel
 * Causes the emulator to set up a TLS tunnel for the host connection. TLS negotiation happens before TELNET negotiation, so the entire session is encrypted.


 * N - Disable TN3270E
 * Disables TN3270E mode. If the host attempts to negotiate TN3270E when this prefix is in use, the emulator will reject it.


 * T - No-TELNET host
 * Disables the TELNET protocol for the session. The emulator will no longer treat the TELNET IAC character (0xff) specially.


 * Y - Disable TLS host certificate checking
 * Disables TLS host certificate checking. It overrides the value of the verifyHostCert resource.

Host
The host is either a fully-qualified domain name (e.g., ) or a numeric address in either IPv4 dotted-decimal or IPv6 hexadecimal format. A numeric IPv6 addres must be surrounded by square-bracket characters, e.g.,, to keep the colon characters from being misinterpreted.

Port
The optional port is a number separated from the host name by a colon. It overrides the default value of 23 (the TELNET port).

Accept-name
The optional accept-name is separated from the host and optional port by an equals sign. It overrides the value of the acceptHostname resource, specifying a name to match against the host's TLS certificate.

Examples
Connect to  without a TLS tunnel, on port 23. foo.bar.com Connect to  with a TLS tunnel but not verifying the host certificate, on port 9100. L:Y:foo.bar.com:9100 Connect to IPv4 address  on port 23. 1.2.3.4 Connect to IPv6 address  on port 23. [100:200::1] Connect to IPv6 address  on port 9100 with a TLS tunnel, using   to match the name from the host's TLS certificate. L:[100:200::1]:9100=myhost