diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv4remote.pl b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv4remote.pl
index ccc247dec514..5f58eb8e0ca8 100755
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv4remote.pl
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv4remote.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#!/usr/bin/env perl
 #
 # CDDL HEADER START
 #
diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv6remote.pl b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv6remote.pl
index 35bea8e58fa1..fbfcdfdab35f 100755
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv6remote.pl
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/get.ipv6remote.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#!/usr/bin/env perl
 #
 # CDDL HEADER START
 #
diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4localtcp.ksh b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4localtcp.ksh
index 2e3ffec52ba6..1d2a99237068 100755
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4localtcp.ksh
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4localtcp.ksh
@@ -58,12 +58,25 @@ fi
 
 dtrace=$1
 local=127.0.0.1
-tcpport=22
 DIR=/var/tmp/dtest.$$
 
+tcpport=1024
+bound=5000
+while [ $tcpport -lt $bound ]; do
+	nc -z $local $tcpport >/dev/null || break
+	tcpport=$(($tcpport + 1))
+done
+if [ $tcpport -eq $bound ]; then
+	echo "couldn't find an available TCP port"
+	exit 1
+fi
+
 mkdir $DIR
 cd $DIR
 
+# nc will exit when the connection is closed.
+nc -l $local $tcpport &
+
 cat > test.pl <<-EOPERL
 	use IO::Socket;
 	my \$s = IO::Socket::INET->new(
@@ -76,7 +89,7 @@ cat > test.pl <<-EOPERL
 	sleep(2);
 EOPERL
 
-$dtrace -c '/usr/bin/perl test.pl' -qs /dev/stdin <<EODTRACE
+$dtrace -c 'perl test.pl' -qs /dev/stdin <<EODTRACE
 BEGIN
 {
 	ipsend = tcpsend = ipreceive = tcpreceive = 0;
diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4remotetcp.ksh b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4remotetcp.ksh
index 65ede66f5fe9..4c91f0002e86 100755
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4remotetcp.ksh
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.ipv4remotetcp.ksh
@@ -79,7 +79,7 @@ cat > test.pl <<-EOPERL
 	sleep(2);
 EOPERL
 
-$dtrace -c '/usr/bin/perl test.pl' -qs /dev/stdin <<EODTRACE
+$dtrace -c 'perl test.pl' -qs /dev/stdin <<EODTRACE
 BEGIN
 {
 	ipsend = tcpsend = ipreceive = tcpreceive = 0;
diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.localtcpstate.ksh b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.localtcpstate.ksh
index 9668ad5868b8..d7a3780ad49e 100644
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.localtcpstate.ksh
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.localtcpstate.ksh
@@ -82,7 +82,7 @@ cat > test.pl <<-EOPERL
 	sleep(2);
 EOPERL
 
-$dtrace -c '/usr/bin/perl test.pl' -qs /dev/stdin <<EODTRACE
+$dtrace -c 'perl test.pl' -qs /dev/stdin <<EODTRACE
 BEGIN
 {
 	ipsend = tcpsend = ipreceive = tcpreceive = 0;
diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.remotetcpstate.ksh b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.remotetcpstate.ksh
index 67712803d978..271cc7849f7e 100644
--- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.remotetcpstate.ksh
+++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/common/ip/tst.remotetcpstate.ksh
@@ -87,7 +87,7 @@ cat > test.pl <<-EOPERL
 	sleep(2);
 EOPERL
 
-$dtrace -c '/usr/bin/perl test.pl' -qs /dev/stdin <<EODTRACE
+$dtrace -c 'perl test.pl' -qs /dev/stdin <<EODTRACE
 BEGIN
 {
 	ipsend = tcpsend = ipreceive = tcpreceive = 0;