Search code examples
network-programmingudpnetstat

netstat -na : udp and state established?

In an application (voip rtp media server), netstat -na on the server (172.16.226.3 bound to udp port 1286) gives the following line :

udp 0 0 172.16.226.3:1286 172.25.14.11:10000 ESTABLISHED

As an udp connection can not be really "established", it strikes me to see such a line. netstat documentation says that this field is used for tcp connection states, but I am sure that this really is an udp network flow. So : what does it means ? I know (wireshark dump) that my server sends back udp packets from 173.16.226.3:1286 to 172.25.14.11:10000, but I don't see why it should matter...

Os is debian 6.

Solution

  • A UDP socket can be connected via the connect(2) system call, so that the socket will only accept packets from the named peer.

    I expect this is the source of the ESTABLISHED column.