diff -Nru smokeping-2.6.11/debian/changelog smokeping-2.6.11/debian/changelog
--- smokeping-2.6.11/debian/changelog	2015-11-25 17:29:51.000000000 -0500
+++ smokeping-2.6.11/debian/changelog	2019-03-23 14:05:09.000000000 -0400
@@ -1,3 +1,13 @@
+smokeping (2.6.11-2.1) unstable; urgency=medium
+
+  * Fix FPing 4.x usage of protocols: Ubuntu bionic ships smokeping 2.6.11
+    with fping 4.0. The fix for smokeping to work properly with fping 4.0 only
+    entered smokeping before release of 2.7.3, so let's backport the upstream
+    fix so that smokeping functions correctly with fping in this LTS release.
+  * Import fping 4 compatibility patch from 2.7.1 release
+
+ -- Gabriel Filion <gabriel@koumbit.org>  Sat, 23 Mar 2019 14:05:09 -0400
+
 smokeping (2.6.11-2) unstable; urgency=high
 
   * security fix for CVE-2015-0859: code execution via CGI arguments due
diff -Nru smokeping-2.6.11/debian/patches/fping_4_protocol_param.patch smokeping-2.6.11/debian/patches/fping_4_protocol_param.patch
--- smokeping-2.6.11/debian/patches/fping_4_protocol_param.patch	1969-12-31 19:00:00.000000000 -0500
+++ smokeping-2.6.11/debian/patches/fping_4_protocol_param.patch	2019-03-23 14:02:46.000000000 -0400
@@ -0,0 +1,63 @@
+commit 681457d0872057f79e2b2f97fa6ff8b6b415b48c
+Author: Gabriel Filion <lelutin@users.noreply.github.com>
+Date:   Wed Aug 29 04:09:04 2018 -0400
+
+    FPing: create new parameter to force using IPv4 or IPv6 fixes#95 (#125)
+    
+    * FPing: create new parameter to force using IPv4 or IPv6 fixes#95
+    
+    Starting with FPing 3.16, the IPv6 functionality was merged in the main
+    binary and fping now respects the system-wide setting for address
+    resolution. This means that when we add a target that has both an A
+    record and a AAAA record, the probe tests the IPv6 address by default.
+    
+    This breaks the expectation that the FPing probe tests IPv4 and that the
+    FPing6 probe checks IPv6.
+    
+    To restore this, we can now add a parameter to the probes to force the
+    protocol version to be 4 or 6.
+    
+    * FPing: set default value for protocol
+    
+    This ensures we have a meaningful default value. It was suggested by
+    Tobias Oetiker.
+
+diff --git a/lib/Smokeping/probes/FPing.pm b/lib/Smokeping/probes/FPing.pm
+index 8010f5f..5ee23b8 100644
+--- a/lib/Smokeping/probes/FPing.pm
++++ b/lib/Smokeping/probes/FPing.pm
+@@ -119,6 +119,7 @@ sub ping ($){
+     # pinging nothing is pointless
+     return unless @{$self->addresses};
+     my @params = () ;
++    push @params, "-$self->{properties}{protocol}";
+     push @params, "-b$self->{properties}{packetsize}" if $self->{properties}{packetsize};
+     push @params, "-t" . int(1000 * $self->{properties}{timeout}) if $self->{properties}{timeout};
+     push @params, "-i" . int(1000 * $self->{properties}{mininterval});
+@@ -197,6 +198,13 @@ sub probevars {
+ 			_example => 'true',
+ 			_doc => "Send an extra ping and then discarge the first answer since the first is bound to be an outliner.",
+ 
++		},
++		protocol => {
++			_re => '(4|6)',
++			_example => '4',
++			_default => '4',
++			_doc => "Choose if the ping should use IPv4 or IPv6.",
++
+ 		},
+ 		usestdout => {
+ 			_re => '(true|false)',
+diff --git a/lib/Smokeping/probes/FPing6.pm b/lib/Smokeping/probes/FPing6.pm
+index b616a35..480b6cf 100644
+--- a/lib/Smokeping/probes/FPing6.pm
++++ b/lib/Smokeping/probes/FPing6.pm
+@@ -46,6 +46,8 @@ sub probevars {
+       my $self = shift;
+       my $h = $self->SUPER::probevars;
+       $h->{binary}{_example} = "/usr/bin/fping6";
++      $h->{protocol}{_example} = "6";
++      $h->{protocol}{_default} = "6";
+       $h->{sourceaddress}{_re} = "[0-9A-Fa-f:.]+";
+       $h->{sourceaddress}{_example} = "::1";
+       return $h;
diff -Nru smokeping-2.6.11/debian/patches/fping_option_compatibility.patch smokeping-2.6.11/debian/patches/fping_option_compatibility.patch
--- smokeping-2.6.11/debian/patches/fping_option_compatibility.patch	1969-12-31 19:00:00.000000000 -0500
+++ smokeping-2.6.11/debian/patches/fping_option_compatibility.patch	2019-03-23 14:05:09.000000000 -0400
@@ -0,0 +1,21 @@
+commit 72ed1570fbb4ae0b90846625e1a3bd5d2bade531
+Author: Tobias Oetiker <tobi@oetiker.ch>
+Date:   Sun Jun 25 20:19:47 2017 +0200
+
+    fing compatibility update. fix for #90
+
+diff --git a/lib/Smokeping/probes/FPing.pm b/lib/Smokeping/probes/FPing.pm
+index b3bc555..8010f5f 100644
+--- a/lib/Smokeping/probes/FPing.pm
++++ b/lib/Smokeping/probes/FPing.pm
+@@ -67,8 +67,8 @@ sub new($$$)
+     	my $binary = join(" ", $self->binary);
+ 	my $testhost = $self->testhost;
+         my $return = `$binary -C 1 $testhost 2>&1`;
+-        $self->{enable}{S} = (`$binary -h 2>&1` =~ /\s-S\s/);
+-        $self->{enable}{O} = (`$binary -h 2>&1` =~ /\s-O\s/);
++        $self->{enable}{S} = (`$binary -h 2>&1` =~ /\s-S[,\s]/);
++        $self->{enable}{O} = (`$binary -h 2>&1` =~ /\s-O[,\s]/);
+         croak "ERROR: fping ('$binary -C 1 $testhost') could not be run: $return"
+             if $return =~ m/not found/;
+         croak "ERROR: FPing must be installed setuid root or it will not work\n" 
diff -Nru smokeping-2.6.11/debian/patches/series smokeping-2.6.11/debian/patches/series
--- smokeping-2.6.11/debian/patches/series	2015-11-25 17:29:51.000000000 -0500
+++ smokeping-2.6.11/debian/patches/series	2019-03-23 14:05:09.000000000 -0400
@@ -7,3 +7,5 @@
 fix-400d-graph
 fix-paths-inside-executables
 missing-VERSION
+fping_4_protocol_param.patch
+fping_option_compatibility.patch