On Mon, 16 Apr 2007 16:28:22 -0600 Sebastian Kuzminsky <[EMAIL PROTECTED]> wrote:
> I'm seeing some weird behavior in TCP. The issue is perfectly > reproducible using netcat and other programs. This is what I do: > > 1. Open a TCP connection over the loopback (over IPv4). > > 2. Send a couple of bytes of data each way. No problems. > > 3. Wait about 120 hours with no writes on either side of the > connection. > > 4. write() a few bytes to the server's socket. I'd expect the data > to go through, but it doesnt. I see the TCP frame from the > server to the client, but instead of an ACK, the client sends > back a RST. netstat shows the bytes sitting in the server's > socket's send-buffer. > > 5. write a few bytes to the client's socket. The server gets > these immediately. > > 6. On the next server-to-client retransmit, the client gets the > bytes from the server. After this, the connection works normally. > > > The libpcap capture file is here (only shows steps 4-6): > > http://highlab.com/~seb/tcp-idleness-bug > > > The behavior is reproducible on all kernels I've tried: 2.4.32, 2.6.19.1, > and 2.6.20.4. I dont think it's iptables-related, though I'm rerunning > the tests on a machine without iptables to be sure. I'll have results > for you in 120 hours. ;-) > > What server? Some servers do application timeouts. -- Stephen Hemminger <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
