How subnet grouping works – HP Transcend Traffix Manager User Manual
Page 135
Using the SubnetsDB File
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4 If you already have devices showing in the Map, reload the subnets
attributes using the Reload Attributes dialog box, which you access from
the Edit menu in the main window.
5 Create a subnets grouping. See
for
information on how to create a site-specific subnet grouping.
6 Apply the grouping.
How Subnet
Grouping Works
Subnet grouping works in the following way:
■
The subnet address and mask are combined with a Boolean AND
operation to produce a key.
For example, when the subnet address 140.6.0.0 is given the Boolean
AND command with the mask 255.255.0.0 the resulting key is:
140.6.0.0=10001100000001100000000000000000
255.255.0.0=11111111111111110000000000000000
Result of AND=10001100000001100000000000000000
■
To determine whether a device qualifies for a subnet, the key value is
compared with the value created by ANDing the subnet mask with the
device's IP address. If these values are not equal, Traffix Manager does
not accept the devices as part of the subnet.
For example, Traffix Manager has detected a device with the IP
address 140.7.0.6. To determine whether the device qualifies for the
pc subnet, Traffix Manager does the following calculation:
140.7.0.6=10001100000001110000000000000110
255.255.0.0=11111111111111110000000000000000
Result of AND=10001100000001110000000000000000
Since the results are not equal, Traffix Manager concludes that the
device is not part of the pc subnet.
■
When matching subnets and devices, Traffix Manager assumes that
the best match for a device is the subnet with the most set bits in the
mask.