130 | 802.1Xw w w . d e l l . c o m | s u p p o r t . d e l l . c o mDynamic CoS with 802.1XDynamic CoS with 802.1X is supported on platforms: c sClass of Service (CoS) is a method of traffic management that groups similar types of traffic so that theyare serviced differently. One way of classifying traffic is 802.1p, which uses the 3-bit Priority field in theVLAN tag to mark frames (other classification methods include ToS, ACL, and DSCP). Once traffic isclassified, you can use Quality of Service (QoS) traffic management to control the level of service for aclass in terms of bandwidth and delivery time.For incoming traffic, FTOS allows you to set a static priority value on a per-port basis or dynamically set apriority on a per-port basis by leveraging 802.1X.One use for Dynamic CoS with 802.1X is when the traffic from a server should be classified based on theapplication that it is running. Static dot1p priority configuration done from the switch is not sufficient inthis case, as the server application might change. You would instead need to push the CoS configuration tothe switches based on the application the server is running.Dynamic CoS uses RADIUS attribute 59, called User-Priority-Table, to specify the priority value forincoming frames. Attribute 59 has an 8-octet field that maps the incoming dot1p values to new values; it isessentially a dot1p re-mapping table. The position of each octet corresponds to a priority value: the firstoctet maps to incoming priority 0, the second octet maps to incoming priority 1, etc. The value in eachoctet represents the corresponding new priority.To use the Dynamic CoS with 802.1X authentication, no configuration command is required. You mustonly configure the supplicant records on the RADIUS server, including VLAN assignment and CoSpriority re-mapping table. VLAN and priority values are automatically applied to incoming packets. TheRADIUS server finds the appropriate record based on the supplicant’s credentials and sends the priorityre-mapping table to the Dell Force10 system by including Attribute 59 in the AUTH-ACCEPT packet.Note: When priority is statically configured using dynamic dot1p and dynamically configured usingDynamic CoS with 802.1X, the dynamic configuration takes precedence.
