Concept Guide
When priority-tagged frames ingress an untagged port or hybrid port, the frames are classied to the default VLAN of the port and to a
queue according to their dot1p priority if you congure service-class dynamic dotp or trust dot1p. When priority-tagged
frames ingress a tagged port, the frames are dropped because, for a tagged port, the default VLAN is 0.
Dell EMC Networking OS Behavior: Hybrid ports can receive untagged, tagged, and priority tagged frames. The rate metering calculation
might be inaccurate for untagged ports because an internal assumption is made that all frames are treated as tagged. Internally, the ASIC
adds a 4-bytes tag to received untagged frames. Though these 4-bytes are not part of the untagged frame received on the wire, they are
included in the rate metering calculation resulting in metering inaccuracy.
Conguring Port-Based Rate Policing
If the interface is a member of a VLAN, you may specify the VLAN for which ingress packets are policed.
• Rate policing ingress trac on an interface.
INTERFACE mode
rate police
Example of the rate police Command
The following example shows conguring rate policing.
DellEMC#configure terminal
DellEMC(conf)#interface tengigabitethernet 1/1
DellEMC(conf-if-te-1/1)#rate police 100 40 peak 150 50
DellEMC(conf-if-te-1/1)#end
Conguring Port-Based Rate Shaping
Rate shaping buers, rather than drops, trac exceeding the specied rate until the buer is exhausted. If any stream exceeds the
congured bandwidth on a continuous basis, it can consume all of the buer space that is allocated to the port.
Dell EMC Networking OS Behavior: Rate shaping is eectively rate limiting because of its smaller buer size. Rate shaping on tagged
ports is slightly greater than the congured rate and rate shaping on untagged ports is slightly less than congured rate.
Rate shaping buers, rather than drops, trac exceeding the specied rate until the buer is exhausted. If any stream exceeds the
congured bandwidth on a continuous basis, it can consume all of the buer space that is allocated to the port.
• Apply rate shaping to outgoing trac on a port.
INTERFACE mode
rate shape
• Apply rate shaping to a queue.
QoS Policy mode
rate-shape
Example of rate shape Command
DellEMC#configure terminal
DellEMC(conf)#interface tengigabitethernet 1/1
DellEMC(conf-if-te-1/1)#rate shape 500 50
DellEMC(conf-if-te-1/1)#end
802
Quality of Service (QoS)