netstat -na : udp and state established?

networking udp netstat
KWA picture KWA · May 31, 2012 · Viewed 9.5k times · Source

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.

Answer

sarnold picture sarnold · May 31, 2012

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.

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