Quality of Service (QoS) | 821
On the C-Series and S-Series you can configure service-class dynamic dot1p from CONFIGURATION
mode, which applies the configuration to all interfaces. A CONFIGURATION mode
service-class dynamic
dot1p
entry supersedes any INTERFACE entries. See Mapping dot1p values to service queues on page 834.
Figure 39-3. service-class dynamic dot1p Command Example
Priority-tagged Frames on the Default VLAN
Priority-tagged Frames on the Default VLAN is available only on platforms: e
x
c s
Priority-tagged frames are 802.1Q tagged frames with VLAN ID 0. For VLAN classification these packets
are treated as untagged. However, the dot1p value is still honored when
service-class dynamic dot1p or trust
dot1p
is configured.
When priority-tagged frames ingress an untagged port or hybrid port the frames are classified to the default
VLAN of the port, and to a queue according to their dot1p priority dot1p priority if
service-class dynamic
dotp
or trust dot1p are configured. When priority-tagged frames ingress a tagged port, the frames are
dropped because for a tagged port the default VLAN is 0.
Configure Port-based Rate Policing
Rate policing ingress traffic on an interface using the command rate police from INTERACE mode, as
shown in Figure 39-4. If the interface is a member of a VLAN, you may specify the VLAN for which
ingress packets are policed.
Figure 39-4. Rate Policing Ingress Traffic
Note: You cannot configure service-policy input and service-class dynamic dot1p on the same interface.
FTOS Behavior: Hybrid ports can receive untagged, tagged, and priority tagged frames. The rate metering
calculation might be inaccurate for untagged ports, since 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.
FTOS#config t
FTOS(conf)#interface gigabitethernet 1/0
FTOS(conf-if)#service-class dynamic dot1p
FTOS(conf-if)#end
FTOS#
FTOS#config t
FTOS(conf)#interface gigabitethernet 1/0
FTOS(conf-if)#rate police 100 40 peak 150 50
FTOS(conf-if)#end
FTOS#