Section 2
2-11
GigaFast
The per-port default PVID is defined at PVID register (0x030C~0x0318) which is a
VLAN Table entry index to map to a 12 bit VID. Every port should be assigned to a
unique PVID. The VID of each VLAN Table entry should be different. The Over-
lapped port groups are allowed, this feature make is easily to allow a server port to
be shared between different VLAN groups without the routing through an external
router device.
The VLAN is used to broken the broadcast domain to limit the broadcast scope. The
VLAN Frame Forwarding Rules is defined as follows:
- A received broadcast/multicast frame will only be flood forward to all the VLAN
member ports (“Port Member Set” in the table) of the classified VLAN except the
source port.
- A received unicast frame will be forward to the destination port only its destination
port is in the same VLAN as the source port.
- If the destination port belongs to a different VLAN, the frame will be discarded.
But it is allowed to forward if the leaky VLAN control is enabled.
*Note*
All VLAN group share with the same L2 MAC table (Shared Learning) to learn the MAC
address.
!
Support Port-based VLAN
By setting the register 0x030B to disable the En8021Qaware control bit, the Port-
based VLAN function is enabled and the 802.1Q VLAN tagging is ignored. All other
VLAN Table configurations are not different to Tag-based VLAN function. The VLAN
classification of any incoming packet on a port for Port-based VLAN is defined by the
port PVID. EE2400-SS use the PVID to search VLAN table to get the VLAN member.
!
Support 802.1Q Tag-based VLAN
By setting the register 0x030B to enable the En8021Qaware control bit, the 802.1Q
Tag-based VLAN function is enabled. And then EE2400-SS will act as an 802.1Q
VLAN aware. The VLAN classification is the first step to be done before VLAN table
lookup. To classify a unique VID value to a received frame is defined as follows:
