Value rule
Address rules (Figure 9-8) let you test the numerical value of a particular part of each packet (at a particular offset with a particular mask) for its relation (greater than, less than, equal to, and so forth) to the value you specify.
Figure 9-8. Value rule
The options for a Value rule are described below:
- Length: To specify the length of the value will been get from the packet.
- Signed: To specify whether the value is signed or not.
- Offset From: Use the drop-down list to choose whether you want AthTek NetWalk to get the value starting at the beginning of the packet, the beginning of the IP layer, or the beginning of the application layer. Alternatively, you can have AthTek NetWalk get the value at a specific Offset (in bytes) from the starting point that you choose from the drop-down list.
- Offset: Enter the amount of the offset.
- Mask: Enter the mask of the value. The value get from the packet will be OR with the mask before comparing with the value specified below.
- Byte Order: Use the drop-down list to choose the byte order of the value get from the packet.
- Operator: To specify the relationship of the value get from the packet and the value specified below.
- Value: The value you want to compare with the value get from the packet.