This information includes the additional TFTP options that are
supported and a description of their use.
To view the standard TFTP request parameters and their meanings, refer
to Internet Request for Comments (RFC) 1350. For more information related
to the TFTP options that are described here, see RFCs 1782, 1783, and 1784.
Internet RFC 2090 describes the TFTP multicast option, which has some similarities
to the Subnet Broadcast option. However, the TFTP Multicast option is
not supported at this time. The TFTP Multicast option RFC is mentioned here
as a reference to help understand the Subnet Broadcast option.
The following is a list of supported options and their descriptions:
- blksize
- Null (0h) terminated keyword blksize that is followed by the
requested block size and represented as a null-terminated ASCII string. This
option requests a block size for the requested file transfer instead of using
the default of 512.
- sbroadcast
- Null-terminated keyword sbroadcast that is followed by the subnet
mask of the subnet to which the client is connected. This option indicates
that the client wants to participate in a subnet-directed broadcast group.
The subnet mask that is included with this option is used with the client's
IP address to determine the client's subnet address.
- tsize
- Null-terminated keyword tsize that is followed by a null-terminated
ASCII representation of 0 (30h). This option is a request for the server to
return the file size in an Option Acknowledgment (OACK).