Section 2
2-13
GigaFast
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Insert/Remove VLAN priority tag
EE2400-SS Support the Output Priority tagging control via set register 0x0319~0x031C.
User can set 3 types of VLAN tagging control:
-
Remove the VLAN tag from all tagged frame.
-
Insert priority tag into the untagged high-priority frame. (Set priority field = 7, VID field =
0 for high priority frame.)
-
Insert priority tag into the all untagged frame.
(Set priority field = 7, VID field = 0 for high priority frame; Set priority field = 0, VID field =
0 for low priority frame.)
-
don’t touch. (Not modify the packet)
Note
: The function could be enabled even the VLAN function is not enabled.
Device Features
Setting IGMP Snooping Control register and IP Multicast Router Port Discovery register.
Router port report will show the IP multicast Router port list. Press the Refresh button to read
the register. Press the ‘
Update
’ button to set the registers, and it will set the register to the
selection.
EE2400-SS Support the ASIC based IGMP snooping function which can be enable via register
0x0308 and no other external CPU handling is required. It support the ability to parser the
IGMP control protocol packets and IP multicast data packets to learn the multicast router port
and group address member ports into the multicast address table. EE2400-SS differentiates
between IGMP control protocol packets according to the message type: Router protocol
packets (IGMP query packets and multicast routing protocol packets) and group member
protocol packets (IGMP v1, v2 Report and Leave packets). The multicast table is build up
based on the IGMP report and leave packets. The Multicast Router port is build up based on
the router protocol packets. An IP multicast data packet (Dest. MAC = 0x01005exxxxxx)
received will involves multicast group table lookup and forwarding operations. If the table
lookup returns a hit, the data packet is forwarded to all the member ports. If the multicast
address is not stored in the address table (i.e. lookup miss), the packet is broadcasted to all
ports of the broadcast domain. The Multicast table is combined with L2 MAC table. So the max
entry is 8k entries. For a given multicast entry, the valid port member bit will auto aging out after
about 5 min if the port never received the corresponding group address IGMP report packet
during 5 min.
