Multicast
Multicast Forwarding Overview
239 Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x
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If filtering is enabled, Multicast frames are forwarded to a subset of the ports in the relevant
VLAN as defined in the Multicast Forwarding Data Base (MFDB). Multicast filtering is
enforced on all traffic.
A common way of representing Multicast membership is the (S,G) notation where S is the
(single) source sending a Multicast stream of data, and G is the IPv4 or IPv6 group address. If
a Multicast client can receive Multicast traffic from any source of a specific Multicast group,
this is saved as (*,G).
You can configure one of the following ways of forwarding Multicast frames:
• MAC Group Address—Based on the destination MAC address in the Ethernet frame.
NOTE One or more IP Multicast group addresses can be mapped to a MAC group
address. Forwarding, based on the MAC group address, can result in an IP Multicast
stream being forwarded to ports that have no receiver for the stream.
• IP Group Address—Based on the destination IP address of the IP packet (*,G).
• Source Specific IP Group Address—Based on both the destination IP address and the
source IP address of the IP packet (S,G).
(S,G) is supported by IGMPv3 and MLDv2, while IGMPv1/2 and MLDv1 support only (*.G),
which is just the group ID.
The device supports a maximum of 256 static and dynamic Multicast group addresses.
Only one of filtering options can be configured per VLAN.