> We checked the FD_SETSIZE-Param, its about 1024.
> ulimit -n is set to 16384.
> Has anybody an idea how to increase the FD_SETSIZE on debian
> or how to handle more than 1024 sockets for bind?

I'm given to understand that Linux doesn't support increasing
FD_SETSIZE on the fly; you have to rebuild the system to do that.

The -P2 versions of the patches, which are in internal testing now and
(barring catastrophe) should be released in two more days, have a
workaround for this. If you set ISC_SOCKET_FDSETSIZE to a value
larger than the existing FD_SETSIZE, it'll use that value instead.
So, for example:


The upcoming point-releases (9.5.1, 9.4.3, 9.3.6) won't use select() on
Linux anymore, so the problem will be moot. If you're comfortable using
beta software at your site, you could switch to 9.5.1b1 or 9.4.3b2 now.
(9.3.6b1 was delayed while we worked on the -P2 patches.)

Evan Hunt -- evan_hunt@isc.org
Internet Systems Consortium, Inc.