On Jul 6, 2011, at 12:27 PM, Kevin Oberman wrote: > 1 in 10**6? That is totally excessive.
It's high for a switched LAN, but I'd imagine you remember collision rates on hubs, which might well exceed 1% of the packets when the network is under load. > The Ethernet spec requires no worse than 10**13 and that is far worse than > should ever be seen in the real world. At one in a million, any remotely high > volume transfer will crawl, especially over a long path. 10 Gigabit ethernet wants cabling spec'ed to a BER of 10e-13; standard gigabit ethernet cabling (Cat 5e) supposedly is rated for 10e-10. However, the BER of the cabling doesn't translate directly into octet error count per the NIC statistics, since a bad bit anywhere in a packet causes the entire packet to be dropped with a failed checksum. > If dropped packets ate being reported, the most common cause is fan-in. If > two input ports are both trying to talk a line rate to a single output port, > the buffer will fill an packets will be dropped. Most switches do tail drop, > so queue management is terrible, compounding the effects. Yes, I agree with this as a likely cause. Regards, -- -Chuck _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
