Multicast forwarding methods and apparatuses across autonomous systems

A multicast forwarding method across Autonomous Systems (ASs), wherein the method is applied to a network device, the network device is deployed as both a Bit Forwarding Egress Router (BFER) in a first Bit Indexed Explicit Replication (BIER) domain and a Bit Forwarding Ingress Router (BFIR) in a second BIER domain, the first BIER domain is a BIER domain to which a first AS belongs, the second BIER domain is a BIER domain to which a second AS belongs, and the network device is located in the second AS;

• the method comprises:
• receiving a first multicast packet belonging to a target multicast group for being multicast forwarded in the first BIER domain, wherein the first multicast packet is from a multicast source connected to a first edge node in the first AS, the first edge node serves as a BFIR in the first BIER domain, and the target multicast group is a multicast group to which the multicast source belongs;
• converting, according to BIER multicast forwarding information corresponding to the target multicast group, the first multicast packet originally for being multicast forwarded in the first BIER domain into a second multicast packet for being multicast forwarded in the second BIER domain, wherein the BIER multicast forwarding information is established according to a multicast join packet initiated by a multicast receiver connected to each edge node in the second BIER domain when joining the target multicast group;
• and
• forwarding the second multicast packet in the second BIER domain.

A multicast forwarding apparatus across Autonomous Systems (ASs), wherein the apparatus is applied to a network device, the network device is deployed as both a Bit Forwarding Egress Router (BFER) in a first Bit Indexed Explicit Replication (BIER) domain and a Bit Forwarding Ingress Router (BFIR) in a second BIER domain, the first BIER domain is a BIER domain to which a first AS belongs, the second BIER domain is a BIER domain to which a second AS belongs, and the network device is located in the second AS;

• the apparatus comprises:
• at least one processor;
• at least one non-transitory storage medium storing machine-executable instructions for execution by the at least one processor to perform operations comprising:
• establishing, according to a multicast join packet initiated by a multicast receiver, BIER multicast forwarding information for being multicast forwarded in the second BIER domain, wherein the multicast receiver is connected to a second edge node in the second AS, the second edge node serves as a BFER in the second BIER domain, the multicast join packet is used to join a target multicast group, the target multicast group is a multicast group to which a multicast source connected to a first edge node in the first AS belongs, and the first edge node serves as a BFIR in the first BIER domain;
• and
• modifying a Bit Forwarding Router Identifier (BFR ID) of the second edge node carried in the multicast join packet into a first BFR ID, and continue to send the multicast join packet to the first edge node, wherein the first BFR ID is a BFR ID configured when the network device is deployed as the BFER in the first BIER domain.