Maintained by: NLnet Labs

partial problem resolving kernel-error.de

A. Schulze
Tue May 30 11:36:32 CEST 2017


W.C.A. Wijngaards via Unbound-users:

> The failure you see is in the code for TCP FASTOPEN.  It was enabled
> when you gave the configure option --enable-tfo-client.

TCP FASTOPEN...
your explanation match perfectly to my observation :-)

I just tried to disable any ipfilter on the failing host. that changes  
nothing.
Also I guess the failing host don't support TCP FASTOPEN at all:

# cat /proc/sys/net/ipv4/tcp_fastopen
cat: /proc/sys/net/ipv4/tcp_fastopen: No such file or directory

# uname -r
3.2.0-4-686-pae

Even if compiled in, can I control TCP FASTOPEN usage on application level?

I've other hosts with an without kernel support for TCP FASTOPEN.
Both classes can resolve the domain in question.

On a plattform with broken TCP FASTOPEN support ( even if noct  
supported by the kernel)
I currently cant disable it, I would need an other unbound binary - right?

Andreas