Can multicast packet source MAC addresses be learned

14

Yes, multicast packet source MAC addresses can be learned.

Other related questions:
Does an AR learn the source MAC address of multicast packets
The AR learns MAC addresses of received multicast packets.

Why are source MAC addresses not learned
The causes are as follows: -The device does not receive packets because the link is Down, the interface does not join the VLAN, the interface participates in spanning tree calculation and is blocked, and so on. -Loops cause MAC address flapping. -MAC address learning is disabled or corresponding Sticky MAC address entries already exist. -The number of learned MAC address entries has reached the maximum. -The static or blackhole route is configured.

Can the virtual MAC address be used as the source MAC address of packets
Yes. By default, the firewall uses the physical MAC address to encapsulate Layer-3 service packets. To use the virtual MAC address, run the vrrp virtual-mac enable command in the interface view.

Can an S series switches forward a packet if both the source and destination IP addresses of the packet are multicast addresses
The S5710-C-LI or S5700SI drops packets whose source and destination IP addresses are both multicast addresses. Other switches broadcast such packets in a VLAN.

DAI is enabled on an S series switches, and the source MAC address of an ARP packet is checked against the source MAC address in an Ethernet frame header. Why can an ARP packet with its source MAC address different from that in the Ethernet frame header pass the check
For S series switcheses: In versions earlier than V200R001, a DAI-enabled switch checks ARP packets based on ACL rules delivered to the chip. However, the ARP packet must be sent to the CPU, and the check of the source MAC address in the ARP packet and that in the Ethernet frame header is performed by software. After the DAI check, the packet is not sent to the CPU, so the source MAC address in the ARP packet and that in the Ethernet frame header are not checked. In V200R001 and later versions, a DAI-enabled switch checks ARP packets using software. The ARP packet with its source MAC address different from that in the Ethernet frame header is discarded.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top