Enterasys Networks 9034313-07 manual Configuring Policy Class of Service CoS

Configuring Policy Class of Service (CoS)

Configuring Policy Class of Service (CoS)

Note: It is recommended that you use Enterasys Networks NMS Policy Manager as an alternative to CLI for configuring policy-based CoS on the switches.

The SecureStack C3 supports Class of Service (CoS), which allows you to assign mission‐critical data to a higher priority through the device by delaying less critical traffic during periods of congestion. The higher priority traffic going through the device is serviced first (before lower priority traffic). The Class of Service capability of the device is implemented by a priority queueing mechanism. Class of Service is based on the IEEE 802.1D (802.1p) standard specification, and allows you to define eight priorities (0‐7, with 7 granted highest priority) and up to 8 transmit queues (0‐7) for each port.

By default, policy‐based CoS is disabled on the device, and default or user‐assigned port‐based 802.1D (802.1p) settings are used to determine traffic prioritization. When policy‐based CoS is enabled, the default and user‐assigned policy‐based settings will override port‐based settings described in Chapter 12.

Class of Service functionality can also be used to control broadcast, unknown unicast, and/or multicast flooding. This feature prevents configured ports from being disrupted by a traffic storm by rate‐limiting specific types of packets through those ports. Refer to “About CoS‐Based Flood Control” on page 11‐19 for more information.

About Policy-Based CoS Configurations

Once enabled using the set cos state command, you can add to the policy‐based CoS function by defining new port groupings, and assigning inbound rate limiters. The process for user‐defined CoS configuration involves the following steps and associated commands listed in Procedure 11‐1. An example follows the procedure.

Procedure 11-1 User-Defined CoS Configuration

Step	Task	Command(s)
1.	Enable CoS	set cos state enable
2.	Create CoS IRL port groups	set cos port-config irl
3.	Define physical rate limiters for groups	set cos port-resource irl
4.	Create virtual reference for the IRL resource	set cos reference
	(physical reference) for each port group
5.	Add IRL reference to CoS settings table	set cos settings

Example

This example creates different inbound rate limiters for two port groups and then assigns them to traffic with a CoS setting of 0.

1.Configure two port groups, one for user ports and one for uplink ports and assign ports to the groups. Port group 1.0 will represent user ports, group 2.0 will represent uplink ports.

C3(su)->set cos port-config irl 1.0 name Users ports ge.1.1-46 C3(su)->set cos port-config irl 2.0 name Uplink ports ge.1.47-48

C3(su)->show cos port-config

Inbound Rate Limiting Port Configuration Entries

SecureStack C3 Configuration Guide 11-17