those TCP statistics have nothing to do with traffic passing through the switch ports, that's for traffic to the control plane (FreeBSD)
Mike Williams [[email protected]] wrote: > Hey all, > > Before I punt this to JTAC, has anyone had any experience with > poor/highly-variable TCP throughput from a small stack of EX3300s? > > We've got a stack of 3, one 48 port, and two 24 ports, and since they went in > we can't get reliable TCP transfers transatlantic. > Linux-Linux can go really fast, but involve Windows and we get a pityful > ~100KBps, regardless of tuning done. > Junos is 11.4R2.14. > > It's taken us *forever* to hone in on the issue possible being the EXs, > because who'd have thought a switch couldn't handle packets at a few 10s of > megabytes per second (10-20k PPS x 3). > > To cut a looooooooong story short; > <internet><srx650><ex3300><linux firewall><same ex3300><server> > Linux firewall sees the 2 initial TCP packets correctly, but the server > generally only gets the second one, or if it gets the first it's after the > second. Then we're into a bazillion duplicate acks, out-of-order packets, and > TCP retransmissions. > > I found the 'show system statistics tcp' command a short while ago and it's, > well, "interesting". > > > > show system statistics tcp > fpc0: > -------------------------------------------------------------------------- > Tcp: > 84769061 packets sent > 16676437 data packets (2039615568 bytes) > 1416 data packets retransmitted (1526176 bytes) > 0 resends initiated by MTU discovery > 67141526 ack only packets (23539653 packets delayed) > 0 URG only packets > 0 window probe packets > 22 window update packets > 3468634 control packets > 125994683 packets received > 15916504 acks(for 2039560634 bytes) > 82630576 duplicate acks > 0 acks for unsent data > 25574925 packets received in-sequence(3702132560 bytes) > 43149892 completely duplicate packets(5824 bytes) > 10 old duplicate packets > 5 packets with some duplicate data(2140 bytes duped) > 0 out-of-order packets(0 bytes) > 0 packets of data after window(0 bytes) > 0 window probes > 24585 window update packets > 23 packets received after close > 0 discarded for bad checksums > 0 discarded for bad header offset fields > 0 discarded because packet too short > > > fpc1 and fpc2 have similar numbers, even though these packets have no need to > leave fpc0. There aren't even any active servers off fpc1/2 yet. > fpc0 has been up 33 days, so has seen almost 30 duplicate acks per second > since it booted. > > -- > Mike Williams > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp -- Keep them laughing half the time, scared of you the other half. And always keep them guessing. -- Clair George _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
