When fast update filters (FUFs) are installed on the Packet Forwarding Engine and PIC, the Packet Forwarding Engine and PIC discard packets flowing through gates if they exceed the rate limits set in the FUF. To get accurate statistics for gates, the JUNOS software includes these discarded packets in statistics that it collects for gates.
Collecting statistics on packets that are dropped on a gate can impact system performance. To improve performance, the software can limit the number of FUF terms installed on the Packet Forwarding Engine for a VPG. This limit is the maximum value of the following parameters configured on the router:
To limit the number of FUF terms installed on the Packet Forwarding Engine for a VPG, include the fast-update-filters statement at the [edit services pgcp gateway gateway-name] hierarchy level:
-
fast-update-filters {
-
maximum-fuf-percentage percentage;
-
maximum-terms number-of-terms;
- }