Why does an S series switch generates Layer 2 multicast forwarding entries in only one VLAN

After an S series switch receives Report messages from the same multicast group in different VLANs, Layer 2 multicast entries are generated in only the VLAN where Report messages are generated first. The causes are as follows:
An S5700SI switch running a version earlier than V200R005 or an S5710-C-LI does not generate the same multicast forwarding entry for a multicast group in multiple VLANs. That is, a multicast group can have a forwarding entry only in one VLAN. To solve this problem, configure a multicast VLAN so that multicast data can be distributed to user VLANs through the multicast VLAN.
- The preceding restriction does not apply to the S5700SI, S5710-X-LI, S5700S-28X-LI-AC, S5700S-52X-LI-AC, S5720S-SI, S5720SI, and E600 running V200R005 and later versions. These switches, however, cannot generate the same multicast forwarding entry for a multicast group in multiple multicast VLANs. That is, a multicast group can have a forwarding entry only in one multicast VLAN.
- The S2700 does not allow an interface to function as the outbound interface of the same multicast forwarding entry in multiple VLAN. That is, one interface can function as the outbound interface of a multicast group in only one VLAN. To solve this problem, add each interface to only one VLAN so that a multicast group has different outbound interfaces in different VLANs.

Scroll to top