手动指定要发送数据的网络接口

Question

I have implemented a service which sends and receives data over a tcp socket. Now there are two network interfaces on my machine, which I'm supposed to run the service over two networks.

How can I specify which network interface to send data? (Using Boost::asio or traditional Berkeley sockets, or by using a system call to change kernel's routing table on the fly)

Answer 1

我不知道 Boost，但一般来说，如果您想使用特定接口发送/接收而不是将套接字bind()到该接口的 IP 地址，或者在某些平台上您可以使用setsockopt(SOL_SOCKET, SO_BINDTODEVICE)代替。

Answer 2

Did you tried this, create a socket bind to 0.0.0.0 for receiving packet from all interfaces. Then create one socket for each interface for sending packet. Key thing here is to set REUSEADDRSS option so that socket for sending can bind to address per-interface and sharing the same port of the one receiving packet.

If you are dealing with TCP, an established connection will ready bind to a specific interface. You won't be able to send to that connection by other interfaces.