User Manual

Enterasys X-Pedition User Reference Manual 429
Traffic Prioritization
Layer-3
For Layer-3 (IP and IPX) traffic you can define flows, blueprints, or templates of IP and IPX packet
headers.
• The IP fields are source IP address, destination IP address, UDP/TCP source port, UDP/TCP
destination port, TOS (Type of Service), transport protocol (TCP or UDP), and a list of
incoming interfaces.
• The IPX fields are source network, source node, destination network, destination node, source
port, destination port, and a list of incoming interfaces.
Precedence for Layer-3 Flows
A precedence from 1 - 7 is associated with each field in a flow. The XP uses the precedence value
associated with the fields to break ties if packets match more than one flow. The highest precedence
is 1 and the lowest is 7. Here is the default precedence of the fields:
• IP: destination port (1), destination IP address (2), source port (3), source IP address (4),
TOS (5), interface (6), protocol (7)
• IPX: destination network (1), source network (2), destination node (3), source node (4),
destination port (5), source port (6), interface (7)
Use the qos precedence ip and qos precedence ipx commands to change the default precedence.
Layer-4
For Layer-4 traffic, you can define a flow based on source/destination TCP/UDP port number in
addition to Layer-3 source/destination IP address.
Traffic Prioritization
Layer-2 Flows
QoS policies applied to layer-2 flows allow you to assign priorities based on source and destination
MAC addresses. A QoS policy set for a layer-2 flow allows you to classify the priority of traffic
from:
• A specific source MAC address to a specific destination MAC address (use only when the port
is in flow bridging mode)
• Any source MAC address to a specific destination MAC address
Before applying a QoS policy to a layer-2 flow, you must first determine whether a port is in
address-bridging mode or flow-bridging mode. If a port operates in address-bridging mode
(default), you can specify the priority based on the destination MAC address and a VLAN ID. You