No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


CX11x, CX31x, CX710 (Earlier Than V6.03), and CX91x Series Switch Modules V100R001C10 Configuration Guide 12

The documents describe the configuration of various services supported by the CX11x&CX31x&CX91x series switch modules The description covers configuration examples and function configurations.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Multicast MAC Address

Multicast MAC Address

As defined by the Ethernet frame format, the rightmost bit "1" of the first octet in a 48-bit MAC addresses indicates that it is a multicast MAC address.

When unicast IP packets are transmitted on an Ethernet network, destination MAC addresses encapsulated in the packets at the link layer are the receiver MAC addresses. However, the destination of a multicast data packet is a group with changeable members but not a specific receiver. Therefore, multicast data packets must use multicast MAC addresses at the data link layer. As defined in the IEEE 802.3 standard, the lowest bit in the high byte of the MAC address is the multicast address flag. The bit is 1, representing the multicast MAC address. The broadcast MAC address can be taken as a special type of multicast and is expressed in the format of 0xFFFF-FFFF-FFFF.

Figure 8-116 Multicast MAC address

As defined by the IANA, leftmost 24 bits of an IPv4 multicast MAC address are 0x01005E, the 25th bit is 0, and the rightmost 23 bits are the same as the rightmost 23 bits of a multicast IPv4 address, as shown in Figure 8-117. For example, if the IPv4 multicast address of a group is, the IPv4 multicast MAC address of this group is 01-00-5E-00-01-01.

Figure 8-117 Mapping between an IPv4 multicast address and an IPv4 multicast MAC address

Updated: 2019-08-09

Document ID: EDOC1000041694

Views: 57890

Downloads: 3621

Average rating:
This Document Applies to these Products
Related Version
Related Documents
Previous Next