This application provides a data transmission method, a device, and a network system. The method is applied to a backbone device, and the backbone device is connected to at least two access devices. After obtaining first data that needs to be sent to a first user device, the backbone device determines a first tunnel interface identifier corresponding to the first user device. The first user device is a single-homing user device. The backbone device sends, based on the first tunnel interface identifier, a first data packet including the first data to a first access device of the at least two access devices. The first access device is configured with the first tunnel interface identifier. This can optimize a data forwarding path, implement traffic optimization for the single-homing user device, and reduce traffic pressure of the network system.

A redundant network IP smart failover method and system based on a redundant computer. Each computer in any computer group comprises an IP address switching module, a network status detecting module, and a peer fault detecting module. The IP address switching module is configured to smoothly switch an IP address in the redundant network. The peer fault detecting module is configured to mutually exclusively and stably acquire operation statuses of peer computers and quickly obtain a correct redundant network IP when necessary. The network status detecting module is configured to determine statuses of local and remote networks to facilitate the IP address switching module to smartly switch the IP address. Configuring a network status detecting module and a peer fault detecting module to aid the IP address switching module to allocate IP addresses more smartly can significantly improve reliability of the redundant network and effectively reduce IP conflicts during the redundant network failover process.

The application discloses a multi-link terminal, a method for allocating an address for the multi-link terminal, a network access device and a medium. The method for allocating the address for the multi-link terminal includes following steps: sending, by a logical entity affiliated with the multi-link terminal, an association request message to a network access device, wherein the association request message includes a MAC address of the multi-link terminal; and receiving, by the logical entity, an association response message sent by the network access device, wherein the association response message includes addresses and association identifiers allocated by the network access device for logical entities affiliated with the multi-link terminal, and the addresses for the logical entities include respective link information bits.

A method and apparatus for addressing a message sent from a proxy node to a peer node in a communications network. The proxy node receives from a host node a plurality of multipath messages. Each message of the plurality of multipath messages has an address. The proxy node then applies a rule to assign an address for a single flow message towards the peer node. The single flow message comprises each message of the plurality of multipath messages. The single flow message is then sent towards the peer node.

A second internet protocol network is logically connected to a packet data network connection provided between a user equipment and a first internet protocol network over a radio access network, the second internet protocol network located on a data path from the first internet protocol network to the user equipment. The first internet protocol network represents the highest level internet protocol point of attachment to the packet data network connection. Router advertisements are sent from the second internet protocol network to the user equipment over the radio access network via the packet data network connection.

In one embodiment, a solution is provided wherein redundant routers are treated as a single emulated switch. When a packet is received at a layer 2 edge switch from a host, the layer 2 edge switch may determine a switch identifier for the emulated switch using a destination anycast hardware address contained in the packet. The anycast hardware address may identify an emulated switch comprising a plurality of routers. Then a header may be added to the packet, the header including the switch identifier. Following that, the packet may be forwarded to another layer 2 switch along a shortest path from the layer 2 edge switch to the emulated switch.

A communication terminal communicates protocol data units across a first virtual interface and a shared interface. The first virtual interface corresponds to an upper layer protocol and a first logical network. The shared interface corresponds to a lower layer protocol. The terminal also communicates protocol data units across a second virtual interface and the shared interface, with the second virtual interface corresponding to the upper layer protocol and a second logical network. The first logical network can be a wide area network that includes devices within a premises and devices outside a premises, and the second logical network may be a local area network that only includes devices within the premises.

A method, system, device, or apparatus for selecting an IP address for a message. The method, system, device, or apparatus is used when there are two or more IP addresses for a multihomed device. The method determines an IP address reachable from a destination for the message. The message is generated using the reachable IP address as the hostname of the multihomed device. The generated message is transferred to the destination.

A communication method and a communications apparatus, where the method includes: assigning, by a control plane device, an Internet Protocol (IP) address to a user equipment; obtaining, by the control plane device using a routing policy network element, a routing rule corresponding to the IP address; and sending, by the control plane device, the routing rule and the IP address to the user equipment, where the routing rule is used by the user equipment to determine a source IP address when the user equipment initiates a service.

A packet forwarding method, apparatus, and system in which a host receives a first packet sent by a gateway, and parses the first packet to obtain a source IP address and a source MAC address from the first packet; queries a host cache table, when a mapping relationship between the source IP address and the source MAC address does not exist in the host cache table, saves the mapping relationship between the source IP address and the source MAC address in the host cache table; the host generates a response packet according to the first packet, and queries the host cache table to acquire a first destination MAC address corresponding to a first destination IP address that is in the response packet; and forwards, according to the first destination MAC address, the response packet to an external network by using the gateway.