[syslinux] [PATCH] core/lwip: Avoid 3-second delay for a half-open connection

Michael Brown mcb30 at ipxe.org
Mon Jul 4 03:32:58 PDT 2016

On 04/07/16 08:23, Michael Brown wrote:
> If lwIP encounters a half-open connection (e.g. due to a restarted
> application reusing the same port numbers) it will correctly send a
> RST but will not resend the SYN until one retransmission timeout later
> (approximately three seconds).  This can increase the time taken by
> lpxelinux.0 to fetch its configuration file from a few milliseconds to
> around 30 seconds.
> Fix by immediately retransmitting the SYN whenever a half-open
> connection is detected.

FYI: this patch has been accepted by upstream lwIP:




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