On Wed, 2015-09-02 at 10:54 +0200, Mohammad Rajiullah wrote: > Hi Eric! > > Thanks for the direction. I tried packet drill locally (with the same kernel > Linux 3.18.5 to start with) > with the following script. And it doesn’t show the problem I mentioned. > So the fast retransmit happens after getting the dupack. > It would be good if I could get some information from the calls > from the TCP stack (I have some printk there), but using packet drill I don’t > know at the moment, > how to get that. >
Please do not top post on netdev mailing list. You could try nstat before/after the failure and report anomalies here. > \ > Mohammad > > > // Establish a connection. > 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 > +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 > +0 setsockopt(3, SOL_SOCKET, TCP_NODELAY, [1], 4) = 0 > > +0 bind(3, ..., ...) = 0 > +0 listen(3, 1) = 0 > > +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> > +0 > S. 0:0(0) ack 1 <...> > > +.03 < . 1:1(0) ack 1 win 257 > +0 accept(3, ..., ...) = 4 > > // Send 1 data segment and get an ACK with DATA > +0 write(4, ..., 1000) = 1000 Note the original tcpdump you gave seemed to use len=250, could you try the exact same lengths ? Thanks ! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
