BIND listen backlog too small
barmar at alum.mit.edu
Thu Oct 16 21:26:54 UTC 2014
In article <mailman.1083.1413494517.26362.bind-users at lists.isc.org>,
Shawn Zhou <shawnzhou00 at yahoo.com> wrote:
> While I was investigating potential SYN flooding warning messages on my Linux
> box for our DNS traffic,I was very surprised to see the backlog was set to
> very small numbers for BIND tcp sockets.
> strace showed backlog was '10' for listening socket for port 53 and '128' for
> listening socket for port 953 (rdnc traffic).
> I've restarted BIND after I updated somaxconn but BIND didn't pick up the
> Why doesn't BIND set the backlog to a huge number and let OSes reduce it to
> whatever somaxconn is? Or just set backlog to whatever is is set for
Since TCP queries should be infrequent, why does it need a high backlog?
It seems like it's already increasing it, IIRC the default is 5.
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