excessive TCP duplicate acks?

[Andre Guibert de Bruet]

On Feb 20, 2007, at 2:31 PM, Andrew Gallatin wrote:

> Thanks for reporting this.  I'm glad I'm not the only one who is  
> seeing this!

I discovered this while testing out a new multi-homed bonded-T1  
installation. I was wondering why I was getting no more than ~170KB/ 
s. So far, here are the data points that I have gathered:

- It affects more than one type of NIC (em0).
- It happens regardless of hardware checksum enabled status.
- It happens independent of IP aliasing.
- I tested GENERIC as of Feb 19 and it is affected.
- A kernel from December 15th, 2006 exhibits this problem.
- The affected system is connected to a Linksys 24-port unmanaged  
gigabit switch (I have the exact same hardware working just fine with  
5.5-STABLE on the same switch).

dmesg for -CURRENT system: http://bling.properkernel.com/freebsd/ 
dmesg.boot.txt

Cheers,
Andy

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