Overview
1-4 Introduction
1.1.6 Broadcast Suppression
Broadcast Suppression enables a user to set a desired limit of receive broadcast frames per port/per
second to be forwarded out the other ports on the device. Any broadcast frames above this
specified limit are dropped. In the event that broadcast frames are being suppressed, multicast and
unicast frames continue to be switched.
1.1.7 Port/VLAN Redirect Functions
The port redirect function, also referred to as “Port Mirroring,” is a troubleshooting tool used to
map traffic from a single source port to a single destination port within the device. This feature
allows frames, including those with errors, to be copied and sent to an analyzer or RMON probe.
The analyzer or RMON probe will see the data as if it were directly connected to the LAN segment
of the source port.
The VLAN redirect function is similar to the port redirect function except that the frames received
by the device are redirected to a designated destination port according to the VLAN classification
of the frames received. Multiple VLANs can be directed to the same destination port. The VLAN
redirect function is only supported when the device is operating as an 802.1Q switch.
1.1.8 Traffic Rate Limiting
The Rate Limiting feature enables the SmartSwitch device to have control over traffic rates on a
per-port, per-priority basis. The network administrator can configure a rate limit (from 100 kbps to
1 Gbps) for a given port with an associated list of IEEE 802.1p priorities (which can include one,
some, or all of the eight priority levels defined in 802.1p). Each rate limit is specified as an
inbound or an outbound limit. The combined rate of all traffic on the port that matches the listed
priorities cannot exceed the programmed limit. If the rate exceeds the defined limit, frames are
dropped until the rate falls below the limit.
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 traffic inbound and outbound on the
same port, two rate limit rules must be configured (one inbound and one 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 rate limiting, refer to the SmartSwitch Series 2H253,
2H252, 2H253 and 2H258 Local Management User’s Guide.
NOTE: This rate limiting function is not supported on ports connected to SmartTrunk
ports.