Reference Guide

Figure 11-2. CoPP solution example
Configure Control Plane Policing
The S4810 can process maximum of 4200 PPS (packets per second). Protocols that share a single
queue may experience flaps if one of the protocols receives a high rate of control traffic even
though Per Protocol CoPP is applied. This happens because Queue-Based Rate Limiting is applies
first.
Q7
Q6
Hardware Queue
Rate Limiting
1100 PPS
400 PPS
CPU Software Queue
CoPP Rule
Examples
Per-Protocol
Rate Limiting
OSPF 200 PPS
BGP 100 PPS
STP 100 PPS
ICMP 50 PPS
Protocol to Queue Classification
(Ingress Flow Entries)
Packets
Front End Ports
Q5
Q4
Q3
Q2
Q1
Q0
STP
ICMP
PING
100 PPS
50 PPS
CPU Processes
(OSPF, LACP, STP, ICMP, etc)
STP
ICMP
PING
Q7
Q6
Hardware Queue
Rate Limiting
1100 PPS
400 PPS
CPU Software Queue
Protocol to Queue Classification
(Ingress Flow Entries)
Packets
Front End Ports
Q5
Q4
Q3
Q2
Q1
Q0
STP
ICMP
PING
CPU Processes
(OSPF, LACP, STP, ICMP, etc)
STP
OPSF flood CPU at 1100 PPS
ICMP fails
No CoPP Rules
Q7 receives STP at 1100 pps due to network storm/loop.
The CPU is hit with the entire 1100 pps and the PING attemp fails intermittently.
CoPP restricts the STP control packet rate to the CPU to 100 pps. PING works reliably.