How to bind a socket to specific net_if

[wxd2024]

Greetings,

I am using both ethernet and wifi in the current project. Does setting the default net_if to one of the two before each time socket connect is called force the socket to be bound with the specific net_if? Assume the target ip address is in an ip section of neither net_ifs and and ip_v4 routing picks the default net_if.

Bests
Wang

[nopnop2002]

I haven't tried it, but I think you just need to specify the IP address of the interface you want to bind to.

Code: Select all

SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

sockaddr_in localaddr = {0};
localaddr.sin_family = AF_INET;
// for WiFi
localaddr.sin_addr.s_addr = inet_addr("192.168.10.103");
// for Ethernet
//localaddr.sin_addr.s_addr = inet_addr("192.168.10.104");
bind(s, (sockaddr*)&localaddr, sizeof(localaddr));