Flow Control
Introduction
1-5
Administrators can configure up to four rate limit rules per port; however, each rule must not
include conflicting 802.1p priority values. In order to control inbound and outbound traffic on the
same port, two rate limiting rules must be configured (one for inbound and one for outbound).
Since the rate limiting operation occurs after the processing of the multi-layer classification rules,
the two features can be combined to provide application-aware rate limiting.
For more information about the application of the Rate Limiting function, refer to the Enterasys
Networks
MATRIX E7 Series and SmartSwitch 6000 Series Modules Local Management User’s
Guide
.
1.8
FLOW CONTROL
Flow control is a method of managing the flow of frames between two devices. It ensures that a
transmitting device does not overwhelm a receiving device with data. This is accomplished by the
transmitting device pausing its transmission while the receiving device processes the frames
already received.
The module supports the following two types of flow control, which can be enabled or disabled on
a port-by-port basis.:
•
Frame based 802.3x, which is supported on all Ethernet ports operating in the full-duplex mode.
•
Back Pressure, which is supported on all Ethernet ports operating in the standard mode of
operation.
1.9
GARP SWITCH OPERATION
Some or all ports on the switch may be activated to operate under the Generic Attribute
Registration Protocol (GARP) applications, GARP VLAN Registration Protocol (GVRP) and/or
GARP Multicast Registration Protocol (GMRP).
GARP is a protocol, or set of rules, that outlines a mechanism for propagating the port state and/or
user information throughout a bridged LAN to keep track of users and VLANs on the network
fabric. MAC bridges and end users alike can take part in the registration and de-registration of
GARP attributes such as VLAN and multicast group membership. For more details on how GVRP
and GMRP handle frames under GARP, and how to configure the switch ports to take advantage of
this operation, refer to the Enterasys Networks
MATRIX E7 Series and SmartSwitch 6000 Series
Modules Local Management User’s Guide
.
NOTE:
This
Rate Limiting
function is not supported on ports connected to SmartTrunk
segments.
