diff --git a/libpcap/configure b/libpcap/configure
index 7da9a4b90..d0c01564f 100755
--- a/libpcap/configure
+++ b/libpcap/configure
@@ -664,11 +664,6 @@ DEPENDENCY_CFLAG
 LN_S
 AR
 RANLIB
-YFLAGS
-YACC
-LEXLIB
-LEX_OUTPUT_ROOT
-LEX
 PCAP_SUPPORT_PACKET_RING
 VALGRINDTEST_SRC
 LIBOBJS
@@ -772,9 +767,7 @@ CFLAGS
 LDFLAGS
 LIBS
 CPPFLAGS
-CPP
-YACC
-YFLAGS'
+CPP'
 
 
 # Initialize some variables set by options.
@@ -1452,12 +1445,6 @@ Some influential environment variables:
   CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
-  YACC        The `Yet Another Compiler Compiler' implementation to use.
-              Defaults to the first program found out of: `bison -y', `byacc',
-              `yacc'.
-  YFLAGS      The list of arguments that will be passed by default to $YACC.
-              This script will default YFLAGS to the empty string to avoid a
-              default value of `-d' given by some make applications.
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -7713,264 +7700,6 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: ${enable_yydebug-no}" >&5
 $as_echo "${enable_yydebug-no}" >&6; }
 
-#
-# Look for {f}lex.
-#
-for ac_prog in flex lex
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_LEX+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$LEX"; then
-  ac_cv_prog_LEX="$LEX" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_LEX="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-LEX=$ac_cv_prog_LEX
-if test -n "$LEX"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LEX" >&5
-$as_echo "$LEX" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-  test -n "$LEX" && break
-done
-test -n "$LEX" || LEX=":"
-
-if test "x$LEX" != "x:"; then
-  cat >conftest.l <<_ACEOF
-%%
-a { ECHO; }
-b { REJECT; }
-c { yymore (); }
-d { yyless (1); }
-e { /* IRIX 6.5 flex 2.5.4 underquotes its yyless argument.  */
-    yyless ((input () != 0)); }
-f { unput (yytext[0]); }
-. { BEGIN INITIAL; }
-%%
-#ifdef YYTEXT_POINTER
-extern char *yytext;
-#endif
-int
-main (void)
-{
-  return ! yylex () + ! yywrap ();
-}
-_ACEOF
-{ { ac_try="$LEX conftest.l"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
-$as_echo "$ac_try_echo"; } >&5
-  (eval "$LEX conftest.l") 2>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking lex output file root" >&5
-$as_echo_n "checking lex output file root... " >&6; }
-if ${ac_cv_prog_lex_root+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-
-if test -f lex.yy.c; then
-  ac_cv_prog_lex_root=lex.yy
-elif test -f lexyy.c; then
-  ac_cv_prog_lex_root=lexyy
-else
-  as_fn_error $? "cannot find output from $LEX; giving up" "$LINENO" 5
-fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_lex_root" >&5
-$as_echo "$ac_cv_prog_lex_root" >&6; }
-LEX_OUTPUT_ROOT=$ac_cv_prog_lex_root
-
-if test -z "${LEXLIB+set}"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking lex library" >&5
-$as_echo_n "checking lex library... " >&6; }
-if ${ac_cv_lib_lex+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-
-    ac_save_LIBS=$LIBS
-    ac_cv_lib_lex='none needed'
-    for ac_lib in '' -lfl -ll; do
-      LIBS="$ac_lib $ac_save_LIBS"
-      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-`cat $LEX_OUTPUT_ROOT.c`
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_lex=$ac_lib
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-      test "$ac_cv_lib_lex" != 'none needed' && break
-    done
-    LIBS=$ac_save_LIBS
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_lex" >&5
-$as_echo "$ac_cv_lib_lex" >&6; }
-  test "$ac_cv_lib_lex" != 'none needed' && LEXLIB=$ac_cv_lib_lex
-fi
-
-
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether yytext is a pointer" >&5
-$as_echo_n "checking whether yytext is a pointer... " >&6; }
-if ${ac_cv_prog_lex_yytext_pointer+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  # POSIX says lex can declare yytext either as a pointer or an array; the
-# default is implementation-dependent.  Figure out which it is, since
-# not all implementations provide the %pointer and %array declarations.
-ac_cv_prog_lex_yytext_pointer=no
-ac_save_LIBS=$LIBS
-LIBS="$LEXLIB $ac_save_LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-  #define YYTEXT_POINTER 1
-`cat $LEX_OUTPUT_ROOT.c`
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_prog_lex_yytext_pointer=yes
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_save_LIBS
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_lex_yytext_pointer" >&5
-$as_echo "$ac_cv_prog_lex_yytext_pointer" >&6; }
-if test $ac_cv_prog_lex_yytext_pointer = yes; then
-
-$as_echo "#define YYTEXT_POINTER 1" >>confdefs.h
-
-fi
-rm -f conftest.l $LEX_OUTPUT_ROOT.c
-
-fi
-if test "$LEX" = ":"; then
-	as_fn_error $? "Neither flex nor lex was found." "$LINENO" 5
-fi
-
-#
-# Make sure {f}lex supports the -P, --header-file, and --nounput flags
-# and supports processing our scanner.l.
-#
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for capable lex" >&5
-$as_echo_n "checking for capable lex... " >&6; }
-if ${tcpdump_cv_capable_lex+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if $LEX -P pcap_ --header-file=/dev/null --nounput -t $srcdir/scanner.l > /dev/null 2>&1; then
-	    tcpdump_cv_capable_lex=yes
-	else
-	    tcpdump_cv_capable_lex=insufficient
-	fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $tcpdump_cv_capable_lex" >&5
-$as_echo "$tcpdump_cv_capable_lex" >&6; }
-if test $tcpdump_cv_capable_lex = insufficient ; then
-	as_fn_error $? "$LEX is insufficient to compile libpcap.
- libpcap requires Flex 2.5.31 or later, or a compatible version of lex." "$LINENO" 5
-fi
-
-#
-# Look for yacc/bison/byacc.
-#
-for ac_prog in 'bison -y' byacc
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
-$as_echo_n "checking for $ac_word... " >&6; }
-if ${ac_cv_prog_YACC+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if test -n "$YACC"; then
-  ac_cv_prog_YACC="$YACC" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-    for ac_exec_ext in '' $ac_executable_extensions; do
-  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_YACC="$ac_prog"
-    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-  done
-IFS=$as_save_IFS
-
-fi
-fi
-YACC=$ac_cv_prog_YACC
-if test -n "$YACC"; then
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $YACC" >&5
-$as_echo "$YACC" >&6; }
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-fi
-
-
-  test -n "$YACC" && break
-done
-test -n "$YACC" || YACC="yacc"
-
-
-#
-# Make sure it supports the -p flag and supports processing our
-# grammar.y.
-#
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for capable yacc/bison" >&5
-$as_echo_n "checking for capable yacc/bison... " >&6; }
-if ${tcpdump_cv_capable_yacc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  if $YACC -p pcap_ -o /dev/null $srcdir/grammar.y >/dev/null 2>&1; then
-	    tcpdump_cv_capable_yacc=yes
-	else
-	    tcpdump_cv_capable_yacc=insufficient
-	fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $tcpdump_cv_capable_yacc" >&5
-$as_echo "$tcpdump_cv_capable_yacc" >&6; }
-if test $tcpdump_cv_capable_yacc = insufficient ; then
-	as_fn_error $? "$YACC is insufficient to compile libpcap.
- libpcap requires Bison, a newer version of Berkeley YACC with support
- for reentrant parsers, or another YACC compatible with them." "$LINENO" 5
-fi
-
 #
 # Do various checks for various OSes and versions of those OSes.
 #
diff --git a/libpcap/configure.ac b/libpcap/configure.ac
index 4b35daaeb..93c884186 100644
--- a/libpcap/configure.ac
+++ b/libpcap/configure.ac
@@ -1489,50 +1489,6 @@ if test "$enable_yydebug" = "yes"; then
 fi
 AC_MSG_RESULT(${enable_yydebug-no})
 
-#
-# Look for {f}lex.
-#
-AC_PROG_LEX
-if test "$LEX" = ":"; then
-	AC_MSG_ERROR([Neither flex nor lex was found.])
-fi
-
-#
-# Make sure {f}lex supports the -P, --header-file, and --nounput flags
-# and supports processing our scanner.l.
-#
-AC_CACHE_CHECK([for capable lex], tcpdump_cv_capable_lex,
-	if $LEX -P pcap_ --header-file=/dev/null --nounput -t $srcdir/scanner.l > /dev/null 2>&1; then
-	    tcpdump_cv_capable_lex=yes
-	else
-	    tcpdump_cv_capable_lex=insufficient
-	fi)
-if test $tcpdump_cv_capable_lex = insufficient ; then
-	AC_MSG_ERROR([$LEX is insufficient to compile libpcap.
- libpcap requires Flex 2.5.31 or later, or a compatible version of lex.])
-fi
-
-#
-# Look for yacc/bison/byacc.
-#
-AC_PROG_YACC
-
-#
-# Make sure it supports the -p flag and supports processing our
-# grammar.y.
-#
-AC_CACHE_CHECK([for capable yacc/bison], tcpdump_cv_capable_yacc,
-	if $YACC -p pcap_ -o /dev/null $srcdir/grammar.y >/dev/null 2>&1; then
-	    tcpdump_cv_capable_yacc=yes
-	else
-	    tcpdump_cv_capable_yacc=insufficient
-	fi)
-if test $tcpdump_cv_capable_yacc = insufficient ; then
-	AC_MSG_ERROR([$YACC is insufficient to compile libpcap.
- libpcap requires Bison, a newer version of Berkeley YACC with support
- for reentrant parsers, or another YACC compatible with them.])
-fi
-
 #
 # Do various checks for various OSes and versions of those OSes.
 #