A packet forwarding method, comprising: receiving, by a host, a first packet sent by a client in an external network and forwarded by a gateway, and parsing the first packet, so as to obtain a source Internet Protocol, IP, address and a source Media Access Control, MAC address, that are of the first packet; wherein the source IP address of the first packet is an IP address of the client in the external network, and the source MAC address is a real MAC address of the gateway; wherein the gateway is one of multiple gateways which simultaneously provide a gateway service for hosts in a same network segment, and the multiple gateways form a multi-active gateway; querying, by the host, a host cache table which is different from an Address Resolution Protocol, ARP, table, and when a mapping relationship between the source IP address and the source MAC address does not exist in the host cache table, saving the mapping relationship between the source IP address and the source MAC address in the host cache table; generating, by the host, a response packet according to the first packet, and querying the host cache table, so as to acquire a first destination MAC address corresponding to a first destination IP address that is in the response packet, wherein the first destination IP address is the same as the source IP address, and the first destination MAC address is the real MAC address of the gateway; and sending, by the host, according to the first destination MAC address corresponding to the first destination IP address that is in the response packet, the response packet to the client in the external network by using the gateway. receiving, by a host, a first packet sent by a client in an external network and forwarded by a gateway, and parsing the first packet, so as to obtain a source Internet Protocol, IP, address and a source Media Access Control, MAC address, that are of the first packet; wherein the source IP address of the first packet is an IP address of the client in the external network, and the source MAC address is a real MAC address of the gateway; wherein the gateway is one of multiple gateways which simultaneously provide a gateway service for hosts in a same network segment, and the multiple gateways form a multi-active gateway; querying, by the host, a host cache table which is different from an Address Resolution Protocol, ARP, table, and when a mapping relationship between the source IP address and the source MAC address does not exist in the host cache table, saving the mapping relationship between the source IP address and the source MAC address in the host cache table; generating, by the host, a response packet according to the first packet, and querying the host cache table, so as to acquire a first destination MAC address corresponding to a first destination IP address that is in the response packet, wherein the first destination IP address is the same as the source IP address, and the first destination MAC address is the real MAC address of the gateway; and sending, by the host, according to the first destination MAC address corresponding to the first destination IP address that is in the response packet, the response packet to the client in the external network by using the gateway.