Filter
Top Products
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).
Server to Client TFTP Option Acknowledgment (OACK)
The TFTP server sends an Option Acknowledgment (OACK) to a client in response
to either a read request or a write request that includes additional TFTP options as
described in “Client to Server TFTP Read Request (RRQ) Options” on page 387. An
OACK that the servers sends in response to a transfer request includes only
responses to requested options that the server supports. The server can also send
an OACK to a client subsequently to the start of a subnet broadcast transfer. This is
done to indicate to the client whether it is the master client in a subnet broadcast
file group. An OACK packet that the server sends subsequently to the start of a
subnet broadcast transfer includes the
sbroadcast
option.
The following is a list of supported options and their descriptions:
blksize
Null (0h) terminated
blksize
keyword that is followed by the block size that is
used for this file transfer. It is represented as a null-terminated ASCII string.
This is the response to a requested block size, and the value returned here can
be less than the requested block size. The server determines the block size for
the transfer based on the requested block size, the maximum configured block
size, and possibly the subnet broadcast transfers that are already in progress.
sbroadcast
Null-terminated
sbroadcast
keyword that is followed by a null-terminated ASCII
string that includes the following fields separated by commas:
port
The ASCII representation of the port to which the subnet-directed broadcast
datagrams are broadcast. This is the well-known port that is registered with
the Internet Assigned Number Authority (IANA) with the keyword of
subntbcst_tftp
and a decimal value of 247. This field might be empty in
OACK packets that the server sends subsequently to the start of a subnet
broadcast transfer.
sbid
The ASCII representation of a decimal number that is called the
subnet
broadcast identifier
. Possible values are 0 through 4,294,967,295
(FFFFFFFFh). This is used along with the server source port to determine if
a subnet-directed broadcast datagram is part of a requested transfer. This
field can be empty in OACK packets that the server sends subsequently to
the start of a subnet-based broadcast transfer.
mc
This is either an ASCII (31h) 1 or ASCII 0 (32h) to indicate to the client
whether it is currently the master client. A value of 1 indicates that the client
is the master client, and a value of 0 indicates that the client is not the
master client.
In response to an OACK, the master client must send an ACK to the server.
The master client sets the block number in this ACK to the number of the
block prior to the first block that is required by the master client.
388 OS/400 TCP/IP Configuration and Reference V4R4