Configuring Port-based Control Plane Traffic Protection

Certain switch models make use of an internal rear-facing interface for CPU communication in addition to a special control-port. Other models use the control-port only.

For all these cases, by default 8 queues are available for control plane traffic segregation and rate-limiting on a per internal port basis. The corresponding eight default packet rates (pps) can be displayed with the following command:

CLI (network-admin@switch) > port-cos-rate-setting-show layout-vertical

switch:                 switch

port:                   control-port

ports:                  0

cos0-rate(pps):         5000

cos1-rate(pps):         5000

cos2-rate(pps):         5000

cos3-rate(pps):         5000

cos4-rate(pps):         5000

cos5-rate(pps):         5000

cos6-rate(pps):         5000

cos7-rate(pps):         5000

Internal (rear facing) data and span ports can be present in a system to carry control plane traffic to the CPU, each using 8 separate queues and rates, as shown below in condensed form:

CLI (network-admin@switch) > port-cos-rate-setting-show

port         ports cos0-rate(pps) cos1-rate(pps) cos2-rate(pps) ... cos6-rate(pps) cos7-rate(pps) 

------------ ----- -------------- -------------- -------------- ... -------------- -------------- 

control-port 0     100000         100000         100000         ... 100000         100000         

data-port    117   100000         100000         100000         ... 100000         100000         

span-ports   118   100000         100000         100000         ... 100000         100000    

It is possible to modify the default rate settings in packets per second using the port-cos-rate-setting-modify command: 

CLI (network-admin@switch) > port-cos-rate-setting-modify ?


Update the port cos rate limit

port control-port|data-port|span-ports 


Specify at least one of the following options

cos0-rate unlimited|0..10000000

cos0 rate limit (pps)

cos1-rate unlimited|0..10000000

cos1 rate limit (pps)

cos2-rate unlimited|0..10000000

cos2 rate limit (pps)

cos3-rate unlimited|0..10000000 

cos3 rate limit (pps)

cos4-rate unlimited|0..10000000

cos4 rate limit (pps)

cos5-rate unlimited|0..10000000

cos5 rate limit (pps)

cos6-rate unlimited|0..10000000

cos6 rate limit (pps)

cos7-rate unlimited|0..10000000

cos7 rate limit (pps) 

For example, the Class 0  rate for control traffic can be configured using the following command:

CLI (network-admin@switch) > port-cos-rate-setting-modify port control-port cos0-rate <rate>

In addition, to show the per-queue traffic statistics you can issue the following command:

CLI (network-admin@switch) > port-cos-stats-show port 0 layout vertical

switch:      switch

time:        11:59:15

port:        0

cos0-out:    58.8M

cos0-drops:  180M

cos1-out:    58.8M

cos1-drops:  185M

cos2-out:    0

cos2-drops:  0

cos3-out:    0

cos3-drops:  0

cos4-out:    0

cos4-drops:  0

cos5-out:    0

cos5-drops:  0

cos6-out:    65.5M

cos6-drops:  1.06G

cos7-out:    483K

cos7-drops:  493M

To clear the queue statistics on the internal ports, use the port-cos-stats-clear command.