Client to Server TFTP Read Request (RRQ) Options
The information that follows includes the additional TFTP options that are supported
and a description of their use. Toview 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 TFTPMulticast
option it 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.
Figure 235. Example of Broadcasting over Subnets
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