diff --git a/CHANGES b/CHANGES
index 862174c068..4c151c3a4c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,14 @@
 
+2.5-101 | 2017-03-09 12:20:11 -0500
+
+  * Input's framework's ascii reader is now more resilient.
+
+    By default, the ASCII reader does not fail on errors anymore.
+    If there is a problem parsing a line, a reporter warning is
+    written and parsing continues.  If the file is missing or can't
+    be read, the input thread just tries again on the next heartbeat.
+    (Seth Hall, Johanna Amann)
+
 2.5-92 | 2017-03-03 10:44:14 -0800
 
   * Move most threading to C++11 primitives (mostly). (Johanna Amann)
diff --git a/VERSION b/VERSION
index 540a520883..852a5388a1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5-92
+2.5-101
diff --git a/scripts/base/frameworks/input/readers/ascii.bro b/scripts/base/frameworks/input/readers/ascii.bro
index 1b486ddba0..1d4072e118 100644
--- a/scripts/base/frameworks/input/readers/ascii.bro
+++ b/scripts/base/frameworks/input/readers/ascii.bro
@@ -18,4 +18,33 @@ export {
 
 	## String to use for an unset &optional field.
 	const unset_field = Input::unset_field &redef;
+
+	## Fail on invalid lines. If set to false, the ascii
+	## input reader will jump over invalid lines, reporting
+	## warnings in reporter.log. If set to true, errors in
+	## input lines will be handled as fatal errors for the
+	## reader thread; reading will abort immediately and
+	## an error will be logged to reporter.log.
+	## Individual readers can use a different value using
+	## the $config table.
+	## fail_on_invalid_lines = T was the default behavior
+	## until Bro 2.6.
+	const fail_on_invalid_lines = F &redef;
+
+	## Fail on file read problems. If set to true, the ascii
+	## input reader will fail when encountering any problems
+	## while reading a file different from invalid lines.
+	## Examples of such problems are permission problems, or
+	## missing files.
+	## When set to false, these problems will be ignored. This
+	## has an especially big effect for the REREAD mode, which will
+	## seamlessly recover from read errors when a file is
+	## only temporarily inaccessible. For MANUAL or STREAM files,
+	## errors will most likely still be fatal since no automatic
+	## re-reading of the file is attempted.
+	## Individual readers can use a different value using
+	## the $config table.
+	## fail_on_file_problem = T was the default behavior
+	## until Bro 2.6.
+	const fail_on_file_problem = F &redef;
 }
diff --git a/src/input/readers/ascii/Ascii.cc b/src/input/readers/ascii/Ascii.cc
index 8b609bda04..bedddce075 100644
--- a/src/input/readers/ascii/Ascii.cc
+++ b/src/input/readers/ascii/Ascii.cc
@@ -61,6 +61,8 @@ void Ascii::DoClose()
 
 bool Ascii::DoInit(const ReaderInfo& info, int num_fields, const Field* const* fields)
 	{
+	suppress_warnings = false;
+
 	separator.assign( (const char*) BifConst::InputAscii::separator->Bytes(),
 	                 BifConst::InputAscii::separator->Len());
 
@@ -73,6 +75,9 @@ bool Ascii::DoInit(const ReaderInfo& info, int num_fields, const Field* const* f
 	unset_field.assign( (const char*) BifConst::InputAscii::unset_field->Bytes(),
 	                   BifConst::InputAscii::unset_field->Len());
 
+	fail_on_invalid_lines = BifConst::InputAscii::fail_on_invalid_lines;
+	fail_on_file_problem = BifConst::InputAscii::fail_on_file_problem;
+
 	// Set per-filter configuration options.
 	for ( ReaderInfo::config_map::const_iterator i = info.config.begin(); i != info.config.end(); i++ )
 		{
@@ -87,6 +92,12 @@ bool Ascii::DoInit(const ReaderInfo& info, int num_fields, const Field* const* f
 
 		else if ( strcmp(i->first, "unset_field") == 0 )
 			unset_field.assign(i->second);
+
+		else if ( strcmp(i->first, "fail_on_invalid_lines") == 0 )
+			fail_on_invalid_lines = (strncmp(i->second, "T", 1) == 0);
+
+		else if ( strcmp(i->first, "fail_on_file_problem") == 0 )
+			fail_on_file_problem = (strncmp(i->second, "T", 1) == 0);
 		}
 
 	if ( separator.size() != 1 )
@@ -98,26 +109,51 @@ bool Ascii::DoInit(const ReaderInfo& info, int num_fields, const Field* const* f
 	formatter::Ascii::SeparatorInfo sep_info(separator, set_separator, unset_field, empty_field);
 	formatter = unique_ptr<threading::formatter::Formatter>(new formatter::Ascii(this, sep_info));
 
-	file.open(info.source);
+	return DoUpdate();
+	}
+
+void Ascii::FailWarn(bool is_error, const char *msg, bool suppress_future)
+	{
+	if ( is_error )
+		Error(msg);
+	else
+		{
+		// suppress error message when we are already in error mode.
+		// There is no reason to repeat it every second.
+		if ( ! suppress_warnings )
+			Warning(msg);
+
+		if ( suppress_future )
+			suppress_warnings = true;
+		}
+	}
+
+bool Ascii::OpenFile()
+	{
+	if ( file.is_open() )
+		return true;
+
+	file.open(Info().source);
+
 	if ( ! file.is_open() )
 		{
-		Error(Fmt("Init: cannot open %s", info.source));
-		return false;
+		FailWarn(fail_on_file_problem, Fmt("Init: cannot open %s", Info().source), true);
+
+		return ! fail_on_file_problem;
 		}
 
 	if ( ReadHeader(false) == false )
 		{
-		Error(Fmt("Init: cannot open %s; headers are incorrect", info.source));
+		FailWarn(fail_on_file_problem, Fmt("Init: cannot open %s; problem reading file header", Info().source), true);
+
 		file.close();
-		return false;
+		return ! fail_on_file_problem;
 		}
 
-	DoUpdate();
-
+	suppress_warnings = false;
 	return true;
 	}
 
-
 bool Ascii::ReadHeader(bool useCached)
 	{
 	// try to read the header line...
@@ -128,7 +164,8 @@ bool Ascii::ReadHeader(bool useCached)
 		{
 		if ( ! GetLine(line) )
 			{
-			Error("could not read first line");
+			FailWarn(fail_on_file_problem, Fmt("Could not read input data file %s; first line could not be read",
+							 Info().source), true);
 			return false;
 			}
 
@@ -170,8 +207,9 @@ bool Ascii::ReadHeader(bool useCached)
 				continue;
 				}
 
-			Error(Fmt("Did not find requested field %s in input data file %s.",
-				  field->name, Info().source));
+			FailWarn(fail_on_file_problem, Fmt("Did not find requested field %s in input data file %s.",
+							 field->name, Info().source), true);
+
 			return false;
 			}
 
@@ -182,8 +220,9 @@ bool Ascii::ReadHeader(bool useCached)
 			map<string, uint32_t>::iterator fit2 = ifields.find(field->secondary_name);
 			if ( fit2 == ifields.end() )
 				{
-				Error(Fmt("Could not find requested port type field %s in input data file.",
-					  field->secondary_name));
+				FailWarn(fail_on_file_problem, Fmt("Could not find requested port type field %s in input data file.",
+								 field->secondary_name), true);
+
 				return false;
 				}
 
@@ -193,7 +232,6 @@ bool Ascii::ReadHeader(bool useCached)
 		columnMap.push_back(f);
 		}
 
-
 	// well, that seems to have worked...
 	return true;
 	}
@@ -224,6 +262,9 @@ bool Ascii::GetLine(string& str)
 // read the entire file and send appropriate thingies back to InputMgr
 bool Ascii::DoUpdate()
 	{
+	if ( ! OpenFile() )
+		return ! fail_on_file_problem;
+
 	switch ( Info().mode ) {
 		case MODE_REREAD:
 			{
@@ -231,8 +272,10 @@ bool Ascii::DoUpdate()
 			struct stat sb;
 			if ( stat(Info().source, &sb) == -1 )
 				{
-				Error(Fmt("Could not get stat for %s", Info().source));
-				return false;
+				FailWarn(fail_on_file_problem, Fmt("Could not get stat for %s", Info().source), true);
+
+				file.close();
+				return ! fail_on_file_problem;
 				}
 
 			if ( sb.st_mtime <= mtime ) // no change
@@ -254,8 +297,10 @@ bool Ascii::DoUpdate()
 				if ( Info().mode == MODE_STREAM )
 					{
 					file.clear(); // remove end of file evil bits
-					if ( !ReadHeader(true) )
-						return false; // header reading failed
+					if ( ! ReadHeader(true) )
+						{
+						return ! fail_on_file_problem; // header reading failed
+						}
 
 					break;
 					}
@@ -263,17 +308,7 @@ bool Ascii::DoUpdate()
 				file.close();
 				}
 
-			file.open(Info().source);
-			if ( ! file.is_open() )
-				{
-				Error(Fmt("cannot open %s", Info().source));
-				return false;
-				}
-
-			if ( ReadHeader(false) == false )
-				{
-				return false;
-				}
+			OpenFile();
 
 			break;
 			}
@@ -327,14 +362,23 @@ bool Ascii::DoUpdate()
 
 			if ( (*fit).position > pos || (*fit).secondary_position > pos )
 				{
-				Error(Fmt("Not enough fields in line %s. Found %d fields, want positions %d and %d",
-					  line.c_str(), pos,  (*fit).position, (*fit).secondary_position));
+				FailWarn(fail_on_invalid_lines, Fmt("Not enough fields in line %s. Found %d fields, want positions %d and %d",
+					  line.c_str(), pos, (*fit).position, (*fit).secondary_position));
 
-				for ( int i = 0; i < fpos; i++ )
-					delete fields[i];
+				if ( fail_on_invalid_lines )
+					{
+					for ( int i = 0; i < fpos; i++ )
+						delete fields[i];
 
-				delete [] fields;
-				return false;
+					delete [] fields;
+
+					return false;
+					}
+				else
+					{
+					error = true;
+					break;
+					}
 				}
 
 			Value* val = formatter->ParseValue(stringfields[(*fit).position], (*fit).name, (*fit).type, (*fit).subtype);
@@ -390,6 +434,9 @@ bool Ascii::DoUpdate()
 
 bool Ascii::DoHeartbeat(double network_time, double current_time)
 	{
+	if ( ! OpenFile() )
+		return ! fail_on_file_problem;
+
 	switch ( Info().mode )
 		{
 		case MODE_MANUAL:
diff --git a/src/input/readers/ascii/Ascii.h b/src/input/readers/ascii/Ascii.h
index 20a459968d..7a7fa52590 100644
--- a/src/input/readers/ascii/Ascii.h
+++ b/src/input/readers/ascii/Ascii.h
@@ -55,6 +55,11 @@ protected:
 private:
 	bool ReadHeader(bool useCached);
 	bool GetLine(string& str);
+	bool OpenFile();
+	// Call Warning or Error, depending on the is_error boolean.
+	// In case of a warning, setting suppress_future to true will suppress all future warnings
+	// (by setting suppress_warnings to true, until suppress_warnings is set back to false)
+	void FailWarn(bool is_error, const char *msg, bool suppress_future = false);
 
 	ifstream file;
 	time_t mtime;
@@ -70,6 +75,12 @@ private:
 	string set_separator;
 	string empty_field;
 	string unset_field;
+	bool fail_on_invalid_lines;
+	bool fail_on_file_problem;
+
+	// this is an internal indicator in case the read is currently in a failed state
+	// it's used to suppress duplicate error messages.
+	bool suppress_warnings;
 
 	std::unique_ptr<threading::formatter::Formatter> formatter;
 };
diff --git a/src/input/readers/ascii/ascii.bif b/src/input/readers/ascii/ascii.bif
index 8bb3a96492..80ff4611e7 100644
--- a/src/input/readers/ascii/ascii.bif
+++ b/src/input/readers/ascii/ascii.bif
@@ -5,3 +5,5 @@ const separator: string;
 const set_separator: string;
 const empty_field: string;
 const unset_field: string;
+const fail_on_invalid_lines: bool;
+const fail_on_file_problem: bool;
diff --git a/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines/out b/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines/out
new file mode 100644
index 0000000000..3406639d29
--- /dev/null
+++ b/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines/out
@@ -0,0 +1,26 @@
+{
+[-43] = [b=T, e=SSH::LOG, c=21, p=123/unknown, sn=10.0.0.0/24, a=1.2.3.4, d=3.14, t=1315801931.273616, iv=100.0, s=hurz, ns=4242 HOHOHO, sc={
+2,
+4,
+1,
+3
+}, ss={
+BB,
+AA,
+CC
+}, se={
+
+}, vc=[10, 20, 30], ve=[]],
+[-42] = [b=T, e=SSH::LOG, c=21, p=123/unknown, sn=10.0.0.0/24, a=1.2.3.4, d=3.14, t=1315801931.273616, iv=100.0, s=hurz, ns=4242, sc={
+2,
+4,
+1,
+3
+}, ss={
+BB,
+AA,
+CC
+}, se={
+
+}, vc=[10, 20, 30], ve=[]]
+}
diff --git a/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stderr b/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stderr
new file mode 100644
index 0000000000..337cdcda87
--- /dev/null
+++ b/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stderr
@@ -0,0 +1,8 @@
+warning: ../does-not-exist.dat/Input::READER_ASCII: Init: cannot open ../does-not-exist.dat
+warning: ../does-not-exist.dat/Input::READER_ASCII: Init: cannot open ../does-not-exist.dat
+warning: ../does-not-exist.dat/Input::READER_ASCII: Init: cannot open ../does-not-exist.dat
+error: ../does-not-exist.dat/Input::READER_ASCII: Init: cannot open ../does-not-exist.dat
+error: ../does-not-exist.dat/Input::READER_ASCII: Init failed
+error: ../does-not-exist.dat/Input::READER_ASCII: terminating thread
+warning: ../does-not-exist.dat/Input::READER_ASCII: Could not get stat for ../does-not-exist.dat
+received termination signal
diff --git a/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stdout b/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stdout
new file mode 100644
index 0000000000..39309bc8cf
--- /dev/null
+++ b/testing/btest/Baseline/scripts.base.frameworks.input.missing-file-initially/bro..stdout
@@ -0,0 +1,5 @@
+now it does
+and more!
+now it does
+and more!
+Streaming still works
diff --git a/testing/btest/scripts/base/frameworks/input/invalid-lines.bro b/testing/btest/scripts/base/frameworks/input/invalid-lines.bro
new file mode 100644
index 0000000000..83be1efd09
--- /dev/null
+++ b/testing/btest/scripts/base/frameworks/input/invalid-lines.bro
@@ -0,0 +1,67 @@
+# @TEST-EXEC: btest-bg-run bro bro -b %INPUT
+# @TEST-EXEC: btest-bg-wait 10
+# @TEST-EXEC: btest-diff out
+
+redef exit_only_after_terminate = T;
+redef InputAscii::fail_on_invalid_lines = F;
+
+@TEST-START-FILE input.log
+#separator \x09
+#path	ssh
+#fields	b	i	e	c	p	sn	a	d	t	iv	s	sc	ss	se	vc	ve	ns
+#types	bool	int	enum	count	port	subnet	addr	double	time	interval	string	table	table	table	vector	vector	string
+T	-42	SSH::LOG	21	123	10.0.0.0/24	1.2.3.4	3.14	1315801931.273616	100.000000	hurz	2,4,1,3	CC,AA,BB	EMPTY	10,20,30
+T	-42	SSH::LOG	21	123	10.0.0.0/24	1.2.3.4	3.14	1315801931.273616	100.000000	hurz	2,4,1,3	CC,AA,BB	EMPTY	10,20,30	EMPTY	4242
+T	-43	SSH::LOG	21	123	10.0.0.0/24	1.2.3.4	3.14	1315801931.273616	100.000000	hurz	2,4,1,3	CC,AA,BB	EMPTY	10,20,30	EMPTY	4242 HOHOHO
+T	-41
+@TEST-END-FILE
+
+@load base/protocols/ssh
+
+global outfile: file;
+
+redef InputAscii::empty_field = "EMPTY";
+
+module A;
+
+type Idx: record {
+	i: int;
+};
+
+type Val: record {
+	b: bool;
+	e: Log::ID;
+	c: count;
+	p: port;
+	sn: subnet;
+	a: addr;
+	d: double;
+	t: time;
+	iv: interval;
+	s: string;
+	ns: string;
+	sc: set[count];
+	ss: set[string];
+	se: set[string];
+	vc: vector of int;
+	ve: vector of int;
+};
+
+global servers: table[int] of Val = table();
+global servers2: table[int] of Val = table();
+
+event bro_init()
+	{
+	outfile = open("../out");
+	# first read in the old stuff into the table...
+	Input::add_table([$source="../input.log", $name="ssh", $idx=Idx, $val=Val, $destination=servers]);
+	Input::add_table([$source="../input.log", $name="ssh2", $idx=Idx, $val=Val, $destination=servers2, $config=table(["fail_on_invalid_lines"] = "T")]);
+	}
+
+event Input::end_of_data(name: string, source:string)
+	{
+	print outfile, servers;
+	Input::remove("ssh");
+	close(outfile);
+	terminate();
+	}
diff --git a/testing/btest/scripts/base/frameworks/input/invalidtext.bro b/testing/btest/scripts/base/frameworks/input/invalidtext.bro
index 1de4e96671..3f5b590dec 100644
--- a/testing/btest/scripts/base/frameworks/input/invalidtext.bro
+++ b/testing/btest/scripts/base/frameworks/input/invalidtext.bro
@@ -13,6 +13,7 @@
 @TEST-END-FILE
 
 redef exit_only_after_terminate = T;
+redef InputAscii::fail_on_invalid_lines = T;
 
 global outfile: file;
 
diff --git a/testing/btest/scripts/base/frameworks/input/missing-file-initially.bro b/testing/btest/scripts/base/frameworks/input/missing-file-initially.bro
new file mode 100644
index 0000000000..73fd57284e
--- /dev/null
+++ b/testing/btest/scripts/base/frameworks/input/missing-file-initially.bro
@@ -0,0 +1,49 @@
+# This tests files that don't exist initially and then do later during
+# runtime to make sure the ascii reader is resilient to files missing.
+# It does a second test at the same time which configures the old
+# failing behavior.
+
+# @TEST-EXEC: btest-bg-run bro bro %INPUT
+# @TEST-EXEC: sleep 2; cp does-exist.dat does-not-exist.dat
+# @TEST-EXEC: sleep 2; mv does-not-exist.dat does-not-exist-again.dat; echo "Streaming still works" >> does-not-exist-again.dat
+# @TEST-EXEC: btest-bg-wait -k 3
+# @TEST-EXEC: btest-diff bro/.stdout
+# @TEST-EXEC: btest-diff bro/.stderr
+
+@TEST-START-FILE does-exist.dat
+#separator \x09
+#fields	line
+#types	string
+now it does
+and more!
+@TEST-END-FILE
+
+redef exit_only_after_terminate = T;
+
+@load base/frameworks/input
+
+module A;
+
+type Val: record {
+	line: string;
+};
+
+event line(description: Input::EventDescription, tpe: Input::Event, v: Val)
+	{
+	print v$line;
+	}
+
+event line2(description: Input::EventDescription, tpe: Input::Event, v: Val)
+	{
+	print "DONT PRINT THIS LINE";
+	}
+
+
+event bro_init()
+	{
+	Input::add_event([$source="../does-not-exist.dat", $name="input", $reader=Input::READER_ASCII, $mode=Input::REREAD, $fields=Val, $ev=line, $want_record=T]);
+	Input::add_event([$source="../does-not-exist.dat", $name="inputstream", $reader=Input::READER_ASCII, $mode=Input::STREAM, $fields=Val, $ev=line, $want_record=T]);
+	Input::add_event([$source="../does-not-exist.dat", $name="inputmanual", $reader=Input::READER_ASCII, $mode=Input::MANUAL, $fields=Val, $ev=line, $want_record=T]);
+	Input::add_event([$source="../does-not-exist.dat", $name="input2", $reader=Input::READER_ASCII, $mode=Input::REREAD, $fields=Val, $ev=line2, $want_record=T,
+	                  $config=table(["fail_on_file_problem"] = "T")]);
+	}
diff --git a/testing/btest/scripts/base/frameworks/input/missing-file.bro b/testing/btest/scripts/base/frameworks/input/missing-file.bro
index 08adfe2150..2ec3bb937f 100644
--- a/testing/btest/scripts/base/frameworks/input/missing-file.bro
+++ b/testing/btest/scripts/base/frameworks/input/missing-file.bro
@@ -3,6 +3,7 @@
 # @TEST-EXEC: btest-diff bro/.stderr
 
 redef exit_only_after_terminate = T;
+redef InputAscii::fail_on_file_problem = T;
 
 global outfile: file;
 global try: count;