ZL50408GDC ZARLINK [Zarlink Semiconductor Inc], ZL50408GDC Datasheet - Page 46

• Manufacturer Part Number: ZL50408GDC
• Description: Managed 8-Port 10/100M 1-Port 10/100/1000M Ethernet Switch
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

8.3
For multicast packet forwarding, the device must determine the proper set of ports from which to transmit the
packet based on the VLAN and hash key.
Three functions are required in order to distribute multicast packets to the appropriate destination ports in a port
trunking environment.
•
•
•
For example, port 0,1 and 2 belong to trunk group 0 and port 3 and 4 belong to trunk group 1. A single VLAN is
established in this system with port 0,1,2,3,4,5 and 6 as the members in the VLAN. When a multicast packet is sent
in from port 3, the ZL50408 select port 0,1,2,3,4,5 and 6 as potential destination based on the VLAN. Then port 3
and 4 are removed because they belong to the source port group (trunk group 1). Two ports from trunk group 0 will
be removed based on the hash key. In this example, we assume port 0 and 1 are removed. As a result, port 2,5 and
6 are the only outgoing ports for this multicast packet.
9.0
See Traffic Mirroring application note, ZLAN-50, for more information.
9.1
Packets can be mirrored (duplicated) for network monitor purpose and/or network debug purpose. Three types of
mirroring is available in ZL50408.
1. Source or Destination MAC address based
2. Flow based
3. Port based
In source or destination mac address based mirroring, the “M” bit of the mirroring MAC address in the MCT is set.
Also, the user need to specify the mirroring MAC address is source or destination of the packet. If source is
selected, any packet received with the mirroring MAC address as source MAC address will be copied to the
mirrored port. In the same way, if destination is selected, any packet received with mirroring MAC address as
destination MAC address will be copied to the mirrored port.
In flow based mirroring, a flow is established based on the source and destination mac address pair. When
enabled, a packet with source and destination address match the pre-programmed source and destination mac
address pair will be copied to the mirrored port. In reverse direction (source and destination match pre programmed
destination and source), the flow can also be enabled and the frame will be copied to the mirrored port.
In port based mirroring, traffic from any RMAC port can be mirrored to any RMAC port. The traffic from the source
port can be either ingress or egress traffic. Up to two ports can be setup as mirrored ports. As a result, the traffic
(both ingress and egress) of a specific port can be monitored by setting up both mirrored ports. Once a port is setup
as mirrored port, it cannot be used for regular traffic.
The mirrored port can be any port in the ZL50408.
9.2
To perform remote loop back test, port mirroring can be used to bounce back the packet to the source port to check
the data path.
The CPU needs to setup the remote device through the command channel to enable port mirroring in the remote
device. A CPU packet is send to the port in test in Device A. The packet will be forwarded to the test port, external
Determining the VLAN group it is forwarding port per group.
The source port/group must be excluded from the forwarding.
Select one port per trunk group to forward the packet to. This selection is based on hash key described in
previous section.
Multicast Packet Forwarding
Mirroring Features
Using port mirroring for loop back
Traffic Mirroring
Zarlink Semiconductor Inc.
ZL50408
46
Data Sheet