HP-UX IPQoS A.01.00 Administrator's Guide (October 2005)

HP-UX IPQoS Configuration Files
Filter Blocks
Chapter 470
pri[ority] p
Priority. Valid range is 1 to 2147483647, inclusive.
Use the priority filter attribute to assign relative importance to filters. The lower the
number the higher the priority. Hence, the highest priority is 1.
The priority attribute is only relevant in cases where a packet matches a traffic class in
more than one filter. In such cases, the policy applied to the packet is determined by the policy
using the filter with the highest priority. If the priorities are the same, then the policy
selected is undetermined.
If a packet can match the traffic class specified by more than one filter, assign relatively
higher priorities (lower numeric values) to more restrictive filters and lower priorities to less
restrictive filters. See “Example 3: Packets Can Match Multiple Filters” on page 122 in
Appendix B, “HP-UX IPQoS Configuration File Examples,” for a case that illustrates the
importance of the priority assignment.
If the priority is higher on a less restrictive filter, a warning message is generated. Because
the filter with the lower priority would never be matched, it is not a meaningful filter. In
intersection cases where filters overlap in some attributes, but not all, the presence of
intersecting overlap also generates warning messages on problematic filters.
For all filters where no priority is specified, HP-UX IPQoS assigns an equal lowest possible
priority.