Brocade Fabric OS Administrator's Guide Supporting Fabric OS v6.3.0 (53-1001336-02, November 2009)

Fabric OS Administrator’s Guide 423
53-1001336-02
QoS: Ingress Rate Limiting
18
QoS: Ingress Rate Limiting
Ingress rate limiting is a licensed feature that requires the Adaptive Networking license. Ingress
rate limiting restricts the speed of traffic from a particular device to the switch port. Use ingress
rate limiting for the following situations:
• To reduce existing congestion in the network or proactively avoid congestion.
• To enable you to offer flexible bandwidth limit services based on requirements.
• To enable more important devices to use the network bandwidth during specific services, such
as network backup.
To limit the traffic, you set the maximum speed at which the traffic can flow through a particular
F_Port or FL_Port. For example, if you set the rate limit at 4 Gbps, then traffic from a particular
device is limited to a maximum of 4 Gbps.
Ingress rate limiting enforcement is needed only if the port can run at a speed higher than the rate
limit. For example, if the rate limit is 4 Gbps and the port is only a 2 Gbps port, then ingress rate
limiting is not enforced.
The ingress rate limiting configuration is persistent across reboots.
Note the following considerations about ingress rate limiting:
• Ingress rate limiting is applicable only to F_Ports and FL_Ports.
• Ingress rate limiting is available only on the following platforms: Brocade 300, 5100, 5300,
5410, 5424, 5450, 5480, Brocade Encryption Switch, Brocade DCX, or DCX-4S.
• QoS traffic prioritization takes precedence over ingress rate limiting.
• Ingress rate limiting is not enforced on trunked ports.
Virtual Fabrics considerations: If Virtual Fabrics is enabled, the rate limit configuration on a port is
on a per-logical switch basis. That is, if a port is configured to have a certain rate limit value, and
the port is then moved to a different logical switch, it would have no rate limit applied to it in the
new logical switch. If that same port is moved back to the original logical switch, it would have the
original rate limit take effect again.
Limiting traffic from a particular device
1. Connect to the switch and log in as admin.
2. Enter the portCfgQos
--setratelimit command.
portcfgqos --setratelimit slot/port ratelimit
Example of setting the rate limit on slot 3, port 9 to 4000 Mbps
portcfgqos --setratelimit 3/9 4000
Disabling ingress rate limiting
1. Connect to the switch and log in as admin.
2. Enter the portCfgQos
--resetratelimit command.
portcfgqos --resetratelimit slot/port