Reference Guide
4 2000 VLT NDS
5 400 ARP_REQ IPV6_ICMP_REQ
6 400 ARP_RESP IPV6_ICMP IPV6_ICMP_RESP IPV4_ICMP SSH TELNET TACACS NTP FTP
7 400 RSTP PVST MSTP LACP
8 600 DOT1X LLDP
9 600 IPV6_OSPF IPV4_BGP IPV4_OSPF
10 600 IPV6_DHCP IPV4_DHCP SERVICEABILITY
11 300 OPEN_FLOW
View CoPP statistics
OS10# show control-plane statistics
Queue Packets Bytes Dropped Packets Dropped Bytes
0 0 0 0 0
1 0 0 0 0
2 0 0 0 0
3 0 0 0 0
4 0 0 0 0
5 2 172 0 0
6 0 0 0 0
7 32048 2180484 0 0
8 14140 2569184 0 0
9 0 0 0 0
10 0 0 0 0
11 0 0 0 0
Congestion avoidance
The weighted random early detection (WRED) congestion avoidance mechanism drops packets to prevent buering resources from being
consumed. Network trac is a mixture of packets of dierent trac types or ows, and the rate of some types of trac is greater than
others.
The packet buer resources (ingress and egress buers) are consumed by only one or a few types of trac, leaving no space for other
types. Apply WRED threshold values to a policy-map so that congured trac is prevented from consuming large amounts of BTM
resources.
Congure WRED parameters for a queue and congure the minimum threshold drop rate using the random-detect command. The
minimum threshold is the allowed buer space for the specied trac—for example, 1000 KB on egress. If the 1000 KB is consumed,
packets drop randomly at an exponential rate until the maximum threshold is reached—this is the “early detection” part of WRED.
Before queuing the packet, OS10 assigns a color (also called drop precedence or DP)—yellow or green—to each packet using the color
{yellow | green}
command based on the packet’s DSCP value. DSCP is a 6-bit eld and OS10 uses the rst three bits (LSB) of this
eld (DP) to determine the drop precedence. The last three bits of the DSCP eld are the drop precedence bits.
If the maximum threshold (for example 2000 KB) is reached, all incoming packets are dropped until the used buer space is reduced to
below 2000 KB of the specied trac.
Quality of service
491