TCP packet out-of-order problem

Robert Watson rwatson at
Mon Jan 5 13:13:25 UTC 2009

On Fri, 2 Jan 2009, Lin Jui-Nan Eric wrote:

> After running "netstat -s -p tcp", we found that lots of packets are 
> discarded due to memory problems. We googled for it, and found that sysctl 
> oid "net.inet.tcp.reass.maxsegments" became 0, therefore packets never 
> reassembled.
> Then we checked our /boot/loader.conf and /etc/sysctl.conf, and found that 
> setting kern.ipc.nmbclusters="0" makes net.inet.tcp.reass.maxsegments=0. 
> After setting net.inet.tcp.reass.maxsegments="1600" in /boot/loader.conf, 
> the network works perfectly now.

Was it set to 0 through a configuration error, or did the system auto-tune 

Robert N M Watson
Computer Laboratory
University of Cambridge

> Thank you all for the help!
> _______________________________________________
> freebsd-stable at mailing list
> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at"

More information about the freebsd-stable mailing list