Dynamic Cos With 802.1X - Dell C9000 Series Networking Configuration Manual

Auth-Fail Max-Attempts:
Critical VLAN:
Critical VLAN id:
Mac-Auth-Bypass:
Mac-Auth-Bypass Only:
Static-MAB:
Static-MAB Profile:
Tx Period:
Quiet Period:
ReAuth Max:
Supplicant Timeout:
Server Timeout:
Re-Auth Interval:
Max-EAP-Req:
Host Mode:
Auth PAE State:
Backend State:

Dynamic CoS with 802.1X

Class of Service (CoS) is a method of traffic management that groups similar types of traffic so that they are
serviced differently. One way of classifying traffic is 802.1p, which uses the 3-bit Priority field in the VLAN tag
to mark frames (other classification methods include ToS, ACL, and DSCP). Once traffic is classified, you can
use Quality of Service (QoS) traffic management to control the level of service for a class in terms of
bandwidth and delivery time.
For incoming traffic, the Dell Networking OS allows you to set a static priority value on a per-port basis or
dynamically set a priority on a per-port basis by leveraging 802.1X.
NOTE: When a priority is statically configured using the dynamic dot1p command and dynamically
configured using dynamic CoS with 802.1X, the dynamic configuration takes precedence.
You can use dynamic CoS with 802.1X is when the traffic from a server should be classified based on the
application that it is running. A static dot1p priority configuration applied from the switch is not sufficient in
this case, as the server application might change. You would instead need to push the CoS configuration to
the switches based on the application the server is running.
Dynamic CoS uses RADIUS attribute 59, called User-Priority-Table, to specify the priority value for incoming
frames. Attribute 59 has an 8-octet field that maps the incoming dot1p values to new values; it is essentially a
dot1p re-mapping table. The position of each octet corresponds to a priority value: the first octet maps to
incoming priority 0, the second octet maps to incoming priority 1, etc. The value in each octet represents the
corresponding new priority.
To use dynamic CoS with 802.1X authentication, no configuration command is required. You must only
configure the supplicant records on the RADIUS server, including VLAN assignment and CoS priority re-
mapping table. VLAN and priority values are automatically applied to incoming packets. The RADIUS server
finds the appropriate record based on the supplicant's credentials and sends the priority re-mapping table to
the Dell Networking system by including Attribute 59 in the AUTH-ACCEPT packet.
The following conditions apply to the use of dynamic CoS with 802.1X authentication on the switch:
• In accordance with port-based QoS, incoming dot1p values can be mapped to only four priority values:
0, 2, 4, and 6. If the RADIUS server returns any other dot1p value (1, 3, 5, or 7), the value is not used and
NONE
Disable
NONE
Enable
Disable
Disable
NONE
30 seconds
60 seconds
2
30 seconds
30 seconds
3600 seconds
2
SINGLE_HOST
Authenticated
Idle
802.1X 125