CHAPTER 5: Advanced Setup Menu
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• Mask—A mask is a test pattern that is used to allow certain frame patterns only. You define a code against
which the frame is compared.
To create a mask, toggle to “Yes.” 3 pairs of codes and offsets must be created. The offset defines the point
in the frame at which the comparison is made. For example, an offset of 8 means that the 8th byte is
compared to the code. The offset can be from the 7th byte onwards. The frame is made of 3 different
portions:
• MAC—is at the beginning of the frame.
• LLC—is after the source address in the frame.
• DATA—is after the LLC section in the frame.
For each code-offset pair, select the code format:
• Binary—specify 48 address bits to be either 0, 1, or X (don’t care).
• Hexadecimal—specify 12 hex digits to be 0-F or X (don’t care).
For each code-offset pair, choose True or False.
Every frame, at the designated offsets, is compared to the 3 codes in the mask. If all 3 codes and the True-
False condition match the code written in the frame, the frame passes.
NOTE
Only 1 mask per filter can be defined.
• Status—Toggle between:
• Active.
• Not Active—Not active allows you to define filters which can be stored and used at a later time.
Saving Filter Parameters
All filters are stored in the Flash Memory, thereby preserving them if the power goes down. When filtering is
selected, all of the filters are copied into the RAM. The RAM copy is then used to activate the software-filtering
process. Any filter which is modified (by clearing all, deleting one, or changing a parameter) goes into effect
immediately. The previous filter also remains in effect until the system is rebooted.
To exit filtering and return to the main Setup menu, press Esc. The following prompt appears:
‘up’ (Y/N)?
Press
Y
to save changes in the Flash Memory. Press
N
to cancel your changes. The system loads the previous set
of masks the next time the system is rebooted.
Содержание LB3104A series
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