Abstract: A packet sending method and device. The first node sets a next-hop of the routing information to a next-hop through which the first node reaches the first route source. The destination address of the routing information is the address prefix. When the second route source is superior to the first route source, the first node switches the next-hop of the routing information to a next-hop through which the first node reaches the second route source. Then, the first node adds, to a target packet, path information of a forwarding path from the first node to the second route source according to the switching operation, where a destination address of the target packet matches the address prefix. Finally, the first node forwards the target packet to the second route source through the forwarding path.

Abstract: A packet sending method and device. The first node sets a next-hop of the routing information to a next-hop through which the first node reaches the first route source. The destination address of the routing information is the address prefix. When the second route source is superior to the first route source, the first node switches the next-hop of the routing information to a next-hop through which the first node reaches the second route source. Then, the first node adds, to a target packet, path information of a forwarding path from the first node to the second route source according to the switching operation, where a destination address of the target packet matches the address prefix. Finally, the first node forwards the target packet to the second route source through the forwarding path.

Abstract: A packet sending method and device. The first node sets a next-hop of the routing information to a next-hop through which the first node reaches the first route source. The destination address of the routing information is the address prefix. When the second route source is superior to the first route source, the first node switches the next-hop of the routing information to a next-hop through which the first node reaches the second route source. Then, the first node adds, to a target packet, path information of a forwarding path from the first node to the second route source according to the switching operation, where a destination address of the target packet matches the address prefix. Finally, the first node forwards the target packet to the second route source through the forwarding path.

Abstract: A method is applied to a network comprising a first area and a second area. A first node in the first area obtains aggregated routing information, where the aggregated routing information is obtained by aggregating a plurality of pieces of original routing information, the plurality of pieces of original routing information correspond to N nodes in a network segment, the N nodes in the network segment have a same flexible algorithm flex-algo, and the aggregated routing information carries an algorithm identifier used to indicate the flex-algo and a network segment identifier used to indicate the network segment. The first node sends the aggregated routing information to the second area, where the aggregated routing information is used to indicate a node in the second area to send a packet to the N nodes in the network segment based on the aggregated routing information.

Abstract: A packet sending method and device. The first node sets a next-hop of the routing information to a next-hop through which the first node reaches the first route source. The destination address of the routing information is the address prefix. When the second route source is superior to the first route source, the first node switches the next-hop of the routing information to a next-hop through which the first node reaches the second route source. Then, the first node adds, to a target packet, path information of a forwarding path from the first node to the second route source according to the switching operation, where a destination address of the target packet matches the address prefix. Finally, the first node forwards the target packet to the second route source through the forwarding path.

Abstract: A bit error information transfer method, a network device, and a communications system are provided, so as to resolve a problem that an existing BFD mechanism cannot be applied to a layer 2 network and cannot be widely applied. In some feasible implementation manners of the application, the method includes: detecting, by a second network device, whether a bit error occurs on a first unidirectional link from a first network device to the second network device; when detecting that a bit error occurs on the first unidirectional link, generating an ISIS packet including bit error information, where the bit error information is used to indicate that the bit error occurs on the first unidirectional link; and sending the ISIS packet to the first network device.

Abstract: A bit error information transfer method, a network device, and a communications system are provided, so as to resolve a problem that an existing BFD mechanism cannot be applied to a layer 2 network and cannot be widely applied. In some feasible implementation manners of the application, the method includes: detecting, by a second network device, whether a bit error occurs on a first unidirectional link from a first network device to the second network device; when detecting that a bit error occurs on the first unidirectional link, generating an ISIS packet including bit error information, where the bit error information is used to indicate that the bit error occurs on the first unidirectional link; and sending the ISIS packet to the first network device.