ripped from SuSE

 if /etc/resolv.conf is updated, then make sure applications

 already running get the updated information.

 http://bugs.gentoo.org/177416

 diff -durN glibc-2.13.orig/resolv/res_libc.c glibc-2.13/resolv/res_libc.c

 --- glibc-2.13.orig/resolv/res_libc.c	2009-02-07 05:27:42.000000000 +0100

 +++ glibc-2.13/resolv/res_libc.c	2009-11-13 00:49:59.000000000 +0100

 @@ -22,6 +22,7 @@

  #include <arpa/nameser.h>

  #include <resolv.h>

  #include <bits/libc-lock.h>

 +#include <sys/stat.h>

  /* The following bit is copied from res_data.c (where it is #ifdef'ed

 @@ -95,6 +96,20 @@

  __res_maybe_init (res_state resp, int preinit)

  {

  	if (resp->options & RES_INIT) {

 +		static time_t last_mtime, last_check;

 +		time_t now;

 +		struct stat statbuf;

 +		

 +		time (&now);

 +		if (now != last_check) {

 +			last_check = now;

 +			if (stat (_PATH_RESCONF, &statbuf) == 0 && last_mtime != statbuf.st_mtime) {

 +				last_mtime = statbuf.st_mtime;

 +				atomicinclock (lock);

 +				atomicinc (__res_initstamp);

 +				atomicincunlock (lock);

 +			}

 +		}

  		if (__res_initstamp != resp->_u._ext.initstamp) {

  			if (resp->nscount > 0)

  				__res_iclose (resp, true);