Compaq T1500 manual Options 128+

Configuring Terminal Start-Up Resources 19

Files ending in a .txt name are treated as text files. Any other filename is treated as an RFC-compliant file.

Use of this option requires a TFTP server. Since path names are included in the file, the TFTP server must accept UNIX-style file separators, not DOS-style separators. Likewise, the default transfer mode must be binary, and the file (either format) must be capable of being read by the terminal without modifications (i.e., the terminal does not accept carriage returns at the end of lines).

This provides the ability to give arbitrarily large option data to the terminal, bypassing the limitations of the Maximum DHCP Message Size option and some servers.

Option 43

Option 43 is the industry-standard method for providing vendor-specific option data to network devices. The three disadvantages are: the total length of option 43 (i.e. all vendor specific options) is 255 bytes; the option data is typically hard to enter; and some servers do not maintain different scopes of option data based upon Vendor ID, Client ID, or other device-defining tag. The Option Ids for these options are listed in an earlier table.

Options 128+

There is debate in the DHCP community about whether or not options 128 through 254 are for vendors’ use. If your server is incapable of sending different option 43 values based upon an identifier, if you can not use TFTP, if you do not want to edit binary data, or if the total set of T1500 options is greater than 255 bytes, all T1500- specific options are available as text strings in this option space. All T1500 options have the prefix 0080_ and are described in an earlier table. By default (i.e., without configuring), the terminals request none of the 127 options in this space. By running Setup, the set can be increased. Any T1500 option can be placed anywhere in this option space, since the 0080_ tag is checked to determine whether or not it is a valid option. If you know what option numbers are going to be used, you can use Setup to define the requested set to just this set of option numbers; if you do not know, you can expose the entire option space.