Electronic device and transmission method thereof

An electronic device comprising:

• a virtual private network circuit configured to establish a virtual private network (VPN) and establish an initial routing table corresponding to the virtual private network;
• and
• a packet receiving circuit configured to receive a packet and obtain a network destination of the packet, and transmit the packet and the network destination to the virtual private network circuit;
• wherein the virtual private network circuit determines whether the network destination is directed to a host located in an internal network;
• the virtual private network circuit transmits the packet according to a first process or the virtual private network circuit revises the initial routing table to generate an updated routing table and then transmits the packet according to the updated routing table if it is determined that the network destination is not directed to the host located in the internal network;
• wherein the virtual private network circuit determines whether the network destination exists in the initial routing table, and if it is determined that the network destination does not exist in the initial routing table, the virtual private network circuit determines whether the network destination is directed to the host located in the internal network.