DM8603EP DAVICOM [Davicom Semiconductor, Inc.], DM8603EP Datasheet - Page 82

• Manufacturer Part Number: DM8603EP
• Description: 10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
• Manufacturer: DAVICOM [Davicom Semiconductor, Inc.]

9.2.17 IGMP Snooping
membership of Internet Protocol multicast groups. IGMP is used by IP hosts and adjacent multicast routers
to establish multicast group memberships. There are three versions of IGMP, as defined by "Request for
Comments" (RFC) documents of the Internet Engineering Task Force (IETF). IGMP v1 is defined by RFC
1112, IGMP v2 is defined by RFC 2236 and IGMP v3 is defined by RFC 3376.
between hosts and routers. The IGMP snooping switch hears an IGMP report from a host with a given
multicast group address. It adds the host's port number to the multicast list for that group, and when the
switch hears an IGMP Leave, it removes the host's port from the table entry. Finally, switch will only forward
multicast traffic to the hosts interested in that traffic. Therefore, this function can effectively reduce multicast
traffic.
this mode. The DM8603 automatically manipulates and updates IGMP membership table and Multicast table
according to IGMP control packets, such as membership report and leave.
ignored and the group address won’t be registered into multicast address table. After that, the unregistered
IP multicast packets (the destination MAC address can not be found in the multicast address table) will be
treated as normal multicast packets by default. The additional forwarding control method can see the register
REG 14h.1Bh.[3:2].
IGMP Query packets will be treated as router port by default. The router port also can be define as static one
by user (see REG 14h.1Bh.[7]) and the port map of the router port can be programmed at REG
14h.1Bh.[10:8]. Keep in mind that the uP port (Port 2) is never treated as router port. The DM8603 leaves
the router port if the time (Router Present Timeout, 400sec by default) is expired that the port never receives
IGMP Query during this period.
receiving LEAVE, DM8603 deletes the entry directly when Fast Leave is enabled, or waiting until timeout.
Interval) is expired. This timer is programmable in DM8603 and defined by RFC 2236 as ((the Robustness
Variable) times (the Query Interval)) plus (one Query Response Interval). The setting of the Robustness
Variable and the Query Interval can see REG 14h.1Ch.
9.2.18 IPv6 MLD Snooping
is enabled and the MLD packets meet following scenario:
Preliminary datasheet
DM8603-12-DS-P01
November 8, 2010
The DM8603 forwards the IPv6 Multicast Listener Discovery (MLD) packets to the processor port when MLD Snooping
The Internet Group Management Protocol (IGMP) is a communications protocol used to manage the
IGMP snooping is a feature that allows the switch to "listen in" on the IGMP protocol conversation
The DM8603 supports IGMP v1/v2 snooping and the maximal group is 16 without any software effort in
If IGMP membership table is full, the later incoming IGMP Membership Report (Join) packet will be
The DM8603 supports router ports auto-detect and auto-aging mechanism. The port which receives
If receiving V1REPORT or V2REPORT (group join), DM8603 creates new or updates the entry. If
DM8603 removes the entry that was never updated after the timer of host timeout (Group Membership
IPv6 Multicast packets.
The Hop Limit in IPv6 header is 1.
The Next Header in IPv6 header is 3Ah (ICMPv6) or 00h (and next header of hop-by-hop option header is
3Ah).
The Type in ICMP header is 82h (Multicast Listener Query), 83h (Multicast Listener Report) or 84h (Multicast
Listener Done).
10/100 Mbps 3-port Ethernet Switch Controller with MII / RMII Interface
DM8603
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