diff --git a/datapath/datapath.c b/datapath/datapath.c
index 633185c..cb1f223 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -367,7 +367,7 @@ err_unlock:
 static int find_portno(struct datapath *dp)
 {
 	int i;
-	for (i = 0; i < DP_MAX_PORTS; i++)
+	for (i = 1; i < DP_MAX_PORTS; i++)
 		if (dp->ports[i] == NULL)
 			return i;
 	return -EXFULL;
diff --git a/regress/bin/of_kmod_test.pl b/regress/bin/of_kmod_test.pl
index b6b5f0f..783f879 100755
--- a/regress/bin/of_kmod_test.pl
+++ b/regress/bin/of_kmod_test.pl
@@ -22,6 +22,6 @@ sub INT_Handler {
 	exit(1);
 }
 
-push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--common-st-args=kmod");
+push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--port_base=1", "--common-st-args=kmod");
 
 run_regress_test( \&INT_Handler, @ARGV );
diff --git a/regress/bin/of_kmod_veth_test.pl b/regress/bin/of_kmod_veth_test.pl
index 270fa3c..0f08edb 100755
--- a/regress/bin/of_kmod_veth_test.pl
+++ b/regress/bin/of_kmod_veth_test.pl
@@ -22,6 +22,6 @@ sub INT_Handler {
 	exit(1);
 }
 
-push (@ARGV, "--map=$ENV{'OFT_ROOT'}/bin/veth.map", "--root=$ENV{'OFT_ROOT'}", "--common-st-args=kmod_veth");
+push (@ARGV, "--map=$ENV{'OFT_ROOT'}/bin/veth.map", "--root=$ENV{'OFT_ROOT'}", "--port_base=1", "--common-st-args=kmod_veth");
 
 run_regress_test( \&INT_Handler, @ARGV );
diff --git a/regress/bin/of_nf2_test.pl b/regress/bin/of_nf2_test.pl
index 28062ec..7124c78 100755
--- a/regress/bin/of_nf2_test.pl
+++ b/regress/bin/of_nf2_test.pl
@@ -22,6 +22,6 @@ sub INT_Handler {
 	exit(1);
 }
 
-push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--map=$ENV{'OFT_ROOT'}/bin/nf2.map", "--common-st-args=nf2", "--port_base=0");
+push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--map=$ENV{'OFT_ROOT'}/bin/nf2.map", "--port_base=1", "--common-st-args=nf2", "--port_base=0");
 
 run_regress_test( \&INT_Handler, @ARGV );
diff --git a/regress/bin/of_user_test.pl b/regress/bin/of_user_test.pl
index 3036626..6a1bcbf 100755
--- a/regress/bin/of_user_test.pl
+++ b/regress/bin/of_user_test.pl
@@ -22,6 +22,6 @@ sub INT_Handler {
 	exit(1);
 }
 
-push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--common-st-args=user");
+push (@ARGV, "--root=$ENV{'OFT_ROOT'}", "--port_base=1", "--common-st-args=user");
 
 run_regress_test( \&INT_Handler, @ARGV );
diff --git a/regress/bin/of_user_veth_test.pl b/regress/bin/of_user_veth_test.pl
index f4abc7d..63551f9 100755
--- a/regress/bin/of_user_veth_test.pl
+++ b/regress/bin/of_user_veth_test.pl
@@ -22,6 +22,6 @@ sub INT_Handler {
 	exit(1);
 }
 
-push( @ARGV, "--map=$ENV{'OFT_ROOT'}/bin/veth.map", "--root=$ENV{'OFT_ROOT'}", "--common-st-args=user_veth");
+push( @ARGV, "--map=$ENV{'OFT_ROOT'}/bin/veth.map", "--root=$ENV{'OFT_ROOT'}", "--port_base=1", "--common-st-args=user_veth");
 
 run_regress_test( \&INT_Handler, @ARGV );
diff --git a/udatapath/datapath.c b/udatapath/datapath.c
index 130bf25..ac878e3 100644
--- a/udatapath/datapath.c
+++ b/udatapath/datapath.c
@@ -246,7 +246,7 @@ int
 dp_add_port(struct datapath *dp, const char *netdev)
 {
     int port_no;
-    for (port_no = 0; port_no < DP_MAX_PORTS; port_no++) {
+    for (port_no = 1; port_no < DP_MAX_PORTS; port_no++) {
         struct sw_port *port = &dp->ports[port_no];
         if (!port->netdev) {
             return new_port(dp, port, port_no, netdev, NULL);