Table 3.1 shows the format of an SMB header. SMB commands are not required to use all the fields in the SMB header. For example, when a client first attempts to connect to a server, it does not yet have a tree identifier (TID) value - one is assigned after it successfully connects - so a null TID (0xFFFF) is placed in its header field. Other fields may be padded with zeros when not used.
The fields of the SMB header are listed in
Table 3.1.
