Configuring Port-Based Priority For Incoming Packets On The 4100Gl And 6108 Switches; The Role Of 802.1Q Vlan Tagging; Switches - HP Switch 2800 Series Management And Configuration Manual

Configuring Port-Based Priority for Incoming Packets on the 4100gl and 6108 Switches

Configuring Port-Based Priority for
Incoming Packets on the 4100gl and 6108

Switches

Feature
Assigning a priority level to traffic on the basis
of incoming port
When network congestion occurs, it is important to move traffic on the basis
of relative importance. However, without prioritization:
Traffic from less important sources can consume bandwidth and slow
down or halt delivery of more important traffic.
Most traffic from all ports is forwarded as normal priority, and competes
for bandwidth with all other normal-priority traffic, regardless of its
relative importance.
Traffic received in tagged VLAN packets carries a specific 802.1p priority level
(0 - 7) that the switch recognizes and uses to assign packet priority at the
outbound port. With the default port-based priority, the switch handles traffic
received in untagged packets as "Normal" (priority level = 0).
You can assign a priority level to:
Inbound, untagged VLAN packets
Inbound, tagged VLAN packets having a priority level of 0 (zero)
(The switch does not alter the existing priority level of inbound, tagged VLAN
packets carrying a priority level of 1-7.)
Thus, for example, high-priority tagged VLAN traffic received on a port retains
its priority in the switch. However, you have the option of
to assign a priority level to untagged traffic and 0-priority tagged traffic the
port receives.

The Role of 802.1Q VLAN Tagging

An 802.1Q-tagged VLAN packet carries the packet's VLAN assignment and the
802.1p priority setting (0 - 7). (By contrast, an untagged packet does not have
a tag and does not carry a priority setting.) Generally, the switch preserves
and uses a packet's priority setting to determine which outbound queue the
packet belongs in on the outbound port. If the outbound port is a tagged
Port Status and Basic Configuration
Default Menu
Disabled n/a
CLI Web
page 10-32 n/a
iguring the port
10-29