ZT8101 Intel (CPU), ZT8101 Datasheet - Page 34

• Manufacturer Part Number: ZT8101
• Manufacturer: Intel (CPU)

Specifications of ZT8101

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Layer 3 Multicast Routing Protocols
7.2.2
7.2.2.1
34
Table 16. Rules for Outgoing Packets
Table 17. Forwarding Rules for Incoming Multicast Data
Multicast Forwarding between VLANs
When a multicast routing protocol is enabled, such as DVMRP or PIM, the multicast data can be
forwarded to other IP interfaces, if needed. Either software or hardware can be used to forward an
IP multicast packet. The switch currently supports software forwarding.
Software Forwarding
To improve switch performance, IP multicast packets are flooded to the VLAN domain and are not
sent to switch’s CPU. When you enable any multicast routing protocol (DVMRP or PIM-DM), all
of the IP multicast packets are sent to switch’s CPU to do further forwarding processing.
An internal multicast forwarding cache is used to match an incoming IP multicast packet with a
forwarding IP interface. The multicast forwarding cache contains the following information:
When the switch receives an IP multicast packet, it either builds or updates the internal multicast
forwarding cache. The relevant bit in the forwarding bitmap is updated according to the results of
multicast routing protocol exchanges and IGMP reports.
The following tables describe the forwarding rules for multicast data.
The multicast group IP address is used as the table’s index.
IGMP Query
IGMP Group Specific Query (IGMP)
IGMP Group Specific Query (IGMP
Snooping)
Unknown multicast data
Known group member multicast
data
Incoming Multicast Data Packets
•
•
•
The sender’s source IP address
The sender’s multicast group IP address
A bitmap of forwarding IP interfaces
Outgoing Packet Type
Intel
®
NetStructure
TM
ZT 8101 10/100 Ethernet Switch Technical Product Specification
•
• Forwards to the entries in the
•
• Forwards to the entries in the
bitmap for the group.
bitmap for the group.
Builds IP multicast cache.
Builds IP multicast cache.
All VLAN member ports.
Group member ports and router ports.
The ports that received IGMP leave packets and the router
ports.
Behavior
Will be sent to
DVMRP or PIM-DM is enabled.
DVMRP or PIM-DM is enabled.
Remarks