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From: Ian FREISLICH <if@hetzner.co.za>
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Cc: 
Subject: Polling bug (was Re: packets duplicated *massively* on transmit.)
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Ian FREISLICH wrote:
> Hi
> 
> I have two FreeBSD routers:
> 
> In two reasonably busy datacenters.  We're seeing packet loss that
> we traced to a packet ariving on the world-facing interface being
> retransmitted approximately every 10 microseconds or so for 1 to 5
> seconds out of the interface the client is on.

Someone has responded in private mail, but re-reading this it's
possible that I didn't explain the situation too well.

One packet arrives on the uplink interface.  This packet is then
repeated between 60000 and 1500000 times out of the other interface
to the exclusion of all other traffic.  It doesn't do this for every
packet, just once every 500000 or so.

I've discovered that turning polling off on the interfaces stops
these retransmission storms.

Ian

--
Ian Freislich