diff --git a/TODO b/TODO
new file mode 100644
index 0000000..c7e06b0
--- /dev/null
+++ b/TODO
@@ -0,0 +1,5 @@
+- implement -4
+- implement -6
+- test -4
+- test -6
+- fix -m
diff --git a/ci/build-2-install.sh b/ci/build-2-install.sh
index a019b12..247eaef 100755
--- a/ci/build-2-install.sh
+++ b/ci/build-2-install.sh
@@ -11,9 +11,8 @@ fi
 autoreconf -i
 ./configure --enable-ipv4 --enable-ipv6 --prefix=/opt/fping
 make CFLAGS="-g -fprofile-arcs -ftest-coverage"
-## setcap currently doesn't worn anymore on travis-ci
+## setcap currently doesn't work anymore on travis-ci
 #sudo setcap cap_net_raw+ep src/fping
-#sudo setcap cap_net_raw+ep src/fping6
 ## setcap debugging:
 #pwd
 #df -k .
@@ -26,6 +25,4 @@ make CFLAGS="-g -fprofile-arcs -ftest-coverage"
 
 # use setuid, since setcap is not available
 sudo chown root src/fping
-sudo chown root src/fping6
 sudo chmod u+s  src/fping
-sudo chmod u+s  src/fping6
diff --git a/ci/prepare-linux.sh b/ci/prepare-linux.sh
index 41504f1..275a56f 100755
--- a/ci/prepare-linux.sh
+++ b/ci/prepare-linux.sh
@@ -1,7 +1,6 @@
 #!/bin/bash
 
 sudo setcap cap_net_raw+ep src/fping
-sudo setcap cap_net_raw+ep src/fping6
 
 if [[ ! $PATH =~ fping/src ]]; then
     echo "# WARNING: must set PATH:"
diff --git a/ci/test-01-basics.pl b/ci/test-01-basics.pl
index 3119232..c855a27 100755
--- a/ci/test-01-basics.pl
+++ b/ci/test-01-basics.pl
@@ -17,7 +17,7 @@ SKIP: {
     if(system("/sbin/ifconfig | grep inet6") != 0) {
         skip 'No IPv6 on this host', 3;
     }
-    my $cmd = Test::Command->new(cmd => "fping6 ::1");
+    my $cmd = Test::Command->new(cmd => "fping ::1");
     $cmd->exit_is_num(0);
     $cmd->stdout_is_eq("::1 is alive\n");
     $cmd->stderr_is_eq("");
diff --git a/ci/test-04-options-a-b.pl b/ci/test-04-options-a-b.pl
index 2288931..6619597 100755
--- a/ci/test-04-options-a-b.pl
+++ b/ci/test-04-options-a-b.pl
@@ -19,7 +19,7 @@ $cmd->stderr_is_eq("");
 
 # fping -A
 {
-my $cmd = Test::Command->new(cmd => "fping -A localhost");
+my $cmd = Test::Command->new(cmd => "fping -4 -A localhost");
 $cmd->exit_is_num(0);
 $cmd->stdout_is_eq("127.0.0.1 is alive\n");
 $cmd->stderr_is_eq("");
diff --git a/ci/test-05-options-c-e.pl b/ci/test-05-options-c-e.pl
index ec84817..b9f9500 100755
--- a/ci/test-05-options-c-e.pl
+++ b/ci/test-05-options-c-e.pl
@@ -9,7 +9,7 @@ use Test::Command tests => 12;
 
 # fping -c n
 {
-my $cmd = Test::Command->new(cmd => "fping -c 2 -p 100 localhost 127.0.0.1");
+my $cmd = Test::Command->new(cmd => "fping -4 -c 2 -p 100 localhost 127.0.0.1");
 $cmd->exit_is_num(0);
 $cmd->stdout_like(qr{localhost : \[0\], 84 bytes, 0\.\d+ ms \(0\.\d+ avg, 0% loss\)
 127\.0\.0\.1 : \[0\], 84 bytes, 0\.\d+ ms \(0.\d+ avg, 0% loss\)
@@ -24,7 +24,7 @@ $cmd->stderr_like(qr{localhost : xmt/rcv/%loss = 2/2/0%, min/avg/max = 0\.\d+/0\
 
 # fping -C n
 {
-my $cmd = Test::Command->new(cmd => "fping -C 2 -p 100 localhost 127.0.0.1");
+my $cmd = Test::Command->new(cmd => "fping -4 -C 2 -p 100 localhost 127.0.0.1");
 $cmd->exit_is_num(0);
 $cmd->stdout_like(qr{localhost : \[0\], 84 bytes, 0\.\d+ ms \(0\.\d+ avg, 0% loss\)
 127\.0\.0\.1 : \[0\], 84 bytes, 0\.\d+ ms \(0.\d+ avg, 0% loss\)
diff --git a/ci/test-09-option-r-t.pl b/ci/test-09-option-r-t.pl
index 501f70e..eae162d 100755
--- a/ci/test-09-option-r-t.pl
+++ b/ci/test-09-option-r-t.pl
@@ -22,7 +22,7 @@ SKIP: {
     if(system("/sbin/ifconfig | grep inet6") != 0) {
         skip 'No IPv6 on this host', 3;
     }
-    my $cmd = Test::Command->new(cmd => "fping6 -q -R -c3 -p100 ::1");
+    my $cmd = Test::Command->new(cmd => "fping -q -R -c3 -p100 ::1");
     $cmd->exit_is_num(0);
     $cmd->stdout_is_eq("");
     $cmd->stderr_like(qr{::1 : xmt/rcv/%loss = 3/3/0%.*});
@@ -84,12 +84,12 @@ $cmd->stdout_is_eq("127.0.0.1 is alive\n");
 $cmd->stderr_is_eq("");
 }
 
-# fping6 -S
+# fping -S
 SKIP: {
     if(system("/sbin/ifconfig | grep inet6") != 0) {
         skip 'No IPv6 on this host', 3;
     }
-    my $cmd = Test::Command->new(cmd => "fping6 -S ::1 ::1");
+    my $cmd = Test::Command->new(cmd => "fping -S ::1 ::1");
     $cmd->exit_is_num(0);
     $cmd->stdout_is_eq("::1 is alive\n");
     $cmd->stderr_is_eq("");
diff --git a/ci/test-11-nopriv.pl b/ci/test-11-nopriv.pl
index bd2065f..904b382 100755
--- a/ci/test-11-nopriv.pl
+++ b/ci/test-11-nopriv.pl
@@ -7,13 +7,11 @@ if( $^O eq 'darwin' ) {
     plan skip_all => 'Test irrelevant on MacOS';
     exit 0;
 }
-plan tests => 6;
+plan tests => 3;
 
 # run without privileges
 my $fping_bin = `which fping`; chomp $fping_bin;
-my $fping6_bin = `which fping6`; chomp $fping6_bin;
 system("cp $fping_bin /tmp/fping.copy; chmod +x /tmp/fping.copy");
-system("cp $fping6_bin /tmp/fping6.copy; chmod +x /tmp/fping6.copy");
 
 # fping
 {
@@ -22,11 +20,3 @@ $cmd->exit_is_num(4);
 $cmd->stdout_is_eq("");
 $cmd->stderr_like(qr{: can't create socket \(must run as root\?\) : .*\n});
 }
-
-# fping6
-{
-my $cmd = Test::Command->new(cmd => "/tmp/fping6.copy ::1");
-$cmd->exit_is_num(4);
-$cmd->stdout_is_eq("");
-$cmd->stderr_like(qr{: can't create raw socket \(must run as root\?\) : .*\n});
-}
diff --git a/ci/test-13-unknown-host.pl b/ci/test-13-unknown-host.pl
index 8094c05..65c8312 100755
--- a/ci/test-13-unknown-host.pl
+++ b/ci/test-13-unknown-host.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/perl -w
 
-use Test::Command tests => 6;
+use Test::Command tests => 3;
 
 # fping
 {
@@ -9,11 +9,3 @@ $cmd->exit_is_num(2);
 $cmd->stdout_is_eq("");
 $cmd->stderr_like(qr{^nosuchname\.example\.com: .*not (known|found)});
 }
-
-# fping6
-{
-my $cmd = Test::Command->new(cmd => "fping6 nosuchname.example.com");
-$cmd->exit_is_num(2);
-$cmd->stdout_is_eq("");
-$cmd->stderr_like(qr{^nosuchname\.example\.com: .*not (known|found)});
-}
diff --git a/ci/test-14-ping-internet-hosts.pl b/ci/test-14-ping-internet-hosts.pl
index 5e36aa0..6e31053 100755
--- a/ci/test-14-ping-internet-hosts.pl
+++ b/ci/test-14-ping-internet-hosts.pl
@@ -41,12 +41,12 @@ $cmd->stdout_is_eq("google-public-dns-a.google.com (8.8.8.8) is alive\n");
 $cmd->stderr_is_eq("");
 }
 
-# fping6 -A -n
+# fping -A -n (IPv6)
 SKIP: {
     if(system("/sbin/ifconfig | grep inet6.*Scope:Global") != 0) {
         skip 'No IPv6 on this host', 3;
     }
-    my $cmd = Test::Command->new(cmd => "fping6 -n -A 2001:4860:4860::8888");
+    my $cmd = Test::Command->new(cmd => "fping -n -A 2001:4860:4860::8888");
     $cmd->exit_is_num(0);
     $cmd->stdout_is_eq("google-public-dns-a.google.com (2001:4860:4860::8888) is alive\n");
     $cmd->stderr_is_eq("");
diff --git a/src/Makefile.am b/src/Makefile.am
index c518d34..da2299f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -8,4 +8,6 @@ fping_DEPENDENCIES = ../config.h
 if IPV6
 fping_SOURCES += socket6.c
 fping_CFLAGS = $(AM_CFLAGS) -DIPV6
+install-exec-hook:
+	ln -s fping$(EXEEXT) $(DESTDIR)$(sbindir)/fping6
 endif
diff --git a/src/fping.c b/src/fping.c
index df91155..011f021 100644
--- a/src/fping.c
+++ b/src/fping.c
@@ -235,18 +235,15 @@ HOST_ENTRY *ev_last;
 char *prog;
 int ident;                  /* our pid */
 int socket4 = 0;
-#ifndef IPV6
-int hints_ai_family = AF_INET;
-#else
-int hints_ai_family = AF_UNSPEC;
-#endif
-
 #ifndef IPV6
 int *allsocket[2] = { &socket4, NULL };
+int hints_ai_family = AF_INET;
 #else
 int socket6 = 0;
 int *allsocket[3] = { &socket4, &socket6, NULL };
+int hints_ai_family = AF_UNSPEC;
 #endif
+
 unsigned int debugging = 0;
 
 /* times get *100 because all times are calculated in 10 usec units, not ms */
@@ -379,17 +376,25 @@ int main( int argc, char **argv )
 
     /* get command line options */
 
-    while( ( c = getopt( argc, argv, "ADMNRadeghlmnoqsuvzB:C:H:I:O:Q:S:T:b:c:f:i:p:r:t:" ) ) != EOF )
+    while( ( c = getopt( argc, argv, "46ADMNRadeghlmnoqsuvzB:C:H:I:O:Q:S:T:b:c:f:i:p:r:t:" ) ) != EOF )
     {
         switch( c )
         {
+        case '4':
+            hints_ai_family = AF_INET;
+            // FIXME: check that -4 and -6 not used together
+            break;
+        case '6':
+            hints_ai_family = AF_INET6;
+            // FIXME: check that -4 and -6 not used together
+            break;
         case 'M':
 #ifdef IP_MTU_DISCOVER
             {
                 int val = IP_PMTUDISC_DO;
-                int *sp;
-                for(sp=allsocket[0]; *sp; sp++) {
-                    if (setsockopt(*sp, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val))) {
+                int **sp;
+                for(sp=&allsocket[0]; *sp; sp++) {
+                    if (setsockopt(**sp, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val))) {
                         perror("setsockopt IP_MTU_DISCOVER");
                     }
                 }
@@ -560,9 +565,9 @@ int main( int argc, char **argv )
         case 'I':
 #ifdef SO_BINDTODEVICE
             {
-                int *sp;
-                for(sp=allsocket[0]; *sp; sp++) {
-                    if (setsockopt(*sp, SOL_SOCKET, SO_BINDTODEVICE, optarg, strlen(optarg))) {
+                int **sp;
+                for(sp=&allsocket[0]; *sp; sp++) {
+                    if (setsockopt(**sp, SOL_SOCKET, SO_BINDTODEVICE, optarg, strlen(optarg))) {
                         perror("binding to specific interface (SO_BINTODEVICE)");
                     }
                 }
@@ -579,9 +584,9 @@ int main( int argc, char **argv )
 
         case 'O':
             if (sscanf(optarg,"%i",&tos)){
-                int *sp;
-                for(sp=allsocket[0]; *sp; sp++) {
-                    if ( setsockopt(*sp, IPPROTO_IP, IP_TOS, &tos, sizeof(tos))) {
+                int **sp;
+                for(sp=&allsocket[0]; *sp; sp++) {
+                    if ( setsockopt(**sp, IPPROTO_IP, IP_TOS, &tos, sizeof(tos))) {
                         perror("setting type of service octet IP_TOS");
                     }
                 }
@@ -735,9 +740,9 @@ int main( int argc, char **argv )
 
     /* set the TTL, if the -H option was set (otherwise ttl will be = 0) */
     if(ttl > 0) {
-        int *sp;
-        for(sp=allsocket[0]; *sp; sp++) {
-            if (setsockopt(*sp, IPPROTO_IP, IP_TTL,  &ttl, sizeof(ttl))) {
+        int **sp;
+        for(sp=&allsocket[0]; *sp; sp++) {
+            if (setsockopt(**sp, IPPROTO_IP, IP_TTL,  &ttl, sizeof(ttl))) {
                 perror("setting time to live");
             }
         }
@@ -746,9 +751,9 @@ int main( int argc, char **argv )
 #if HAVE_SO_TIMESTAMP
     {
         int opt = 1;
-        int *sp;
-        for(sp=allsocket[0]; *sp; sp++) {
-            if (setsockopt(*sp, SOL_SOCKET, SO_TIMESTAMP,  &opt, sizeof(opt))) {
+        int **sp;
+        for(sp=&allsocket[0]; *sp; sp++) {
+            if (setsockopt(**sp, SOL_SOCKET, SO_TIMESTAMP,  &opt, sizeof(opt))) {
                 perror("setting SO_TIMESTAMP option");
             }
         }