RELENG-7 tcp connectivity problems with certain clients
silby at silby.com
Sun Mar 9 01:17:25 PST 2008
On Sun, 9 Mar 2008, Jake Rizzo wrote:
> The patch didn't work, but doing this:
> sysctl net.inet.tcp.tso=0
> sysctl net.inet.tcp.sack.enable=0
> Allows the client to connect again. Since my ifconfig doesn't show that my
> nic supports TSO then I presume it's the sack sysctl that's making it work.
> The machine's a webserver serving almost exclusively dynamic content - with
> sack disabled is it likely to affect performance much?
SACK makes retransmission more effective in some circumstances when packet
loss occurs. So, you're probably not going to notice it being disabled at
all. In fact. FreeBSD 4.x didn't have any SACK support whatsoever.
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