stds-80220-requirements: section 4.1.1.1 Protcol Field Mapping
we have the following text in section 4.1.1.1 Protocol Field
Mapping
Flexible bit-based masking of multiple fields at every layer MUST be made
available for purposes of identifying packets. These matched criterions
include but are not limited to:
L4 Protocol field (UDP/TCP port number)
L4 Header length
L4 TCP flags
L4 TCP options (if present)
L3 Protocol field
L3 Source address/network
L3 Destination address/network
L3 Total length
L3 Fragmentation (Initial 4 bits of two-byte field)
L3 DiffServe/TOS field (to include ECN)
I would like to have the proponent of this text explain how we get flags
from layers 3 and 4, when we do not have an interface to layers 3 and 4. If
th author is referencing a specific specification, what happens when a
second specification does not have these fields?
a. chickinsky