diff --git a/integrationdhcpv4_test.go b/integrationdhcpv4_test.go
index ec4d352..a9f22cc 100644
--- a/integrationdhcpv4_test.go
+++ b/integrationdhcpv4_test.go
@@ -33,6 +33,7 @@ func TestDHCPv4(t *testing.T) {
 	}
 
 	for _, cmd := range nsSetup {
+		cmd.Stderr = os.Stderr
 		if err := cmd.Run(); err != nil {
 			t.Fatalf("%v: %v", cmd.Args, err)
 		}
@@ -45,7 +46,7 @@ func TestDHCPv4(t *testing.T) {
 	ready.Close()                 // dnsmasq will re-create the file anyway
 	defer os.Remove(ready.Name()) // dnsmasq does not clean up its pid file
 
-	dnsmasq := dnsmasq.Run(t)
+	dnsmasq := dnsmasq.Run(t, "veth0b")
 	defer dnsmasq.Kill()
 
 	// f, err := os.Create("/tmp/pcap")
diff --git a/integrationdhcpv6_test.go b/integrationdhcpv6_test.go
index 10312e3..b811003 100644
--- a/integrationdhcpv6_test.go
+++ b/integrationdhcpv6_test.go
@@ -1,6 +1,7 @@
 package integration_test
 
 import (
+	"os"
 	"os/exec"
 	"regexp"
 	"strings"
@@ -23,27 +24,28 @@ func TestDHCPv6(t *testing.T) {
 	defer exec.Command("ip", "netns", "delete", ns).Run()
 
 	nsSetup := []*exec.Cmd{
-		exec.Command("ip", "link", "add", "veth0a", "type", "veth", "peer", "name", "veth0b", "netns", ns),
+		exec.Command("ip", "link", "add", "veth1a", "type", "veth", "peer", "name", "veth1b", "netns", ns),
 
 		// Disable Duplicate Address Detection: until DAD completes, the link-local
 		// address remains in state “tentative”, resulting in any attempts to
 		// bind(2) to the address to fail with -EADDRNOTAVAIL.
-		exec.Command("/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth0a/accept_dad"),
-		exec.Command("ip", "netns", "exec", ns, "/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth0b/accept_dad"),
+		exec.Command("/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth1a/accept_dad"),
+		exec.Command("ip", "netns", "exec", ns, "/bin/sh", "-c", "echo 0 > /proc/sys/net/ipv6/conf/veth1b/accept_dad"),
 
-		exec.Command("ip", "link", "set", "veth0a", "up"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "192.168.23.1/24", "dev", "veth0b"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "2001:db8::1/64", "dev", "veth0b"),
-		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth0b", "up"),
+		exec.Command("ip", "link", "set", "veth1a", "up"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "192.168.23.1/24", "dev", "veth1b"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "2001:db8::1/64", "dev", "veth1b"),
+		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth1b", "up"),
 	}
 
 	for _, cmd := range nsSetup {
+		cmd.Stderr = os.Stderr
 		if err := cmd.Run(); err != nil {
 			t.Fatalf("%v: %v", cmd.Args, err)
 		}
 	}
 
-	dnsmasq := dnsmasq.Run(t)
+	dnsmasq := dnsmasq.Run(t, "veth1b")
 	defer dnsmasq.Kill()
 
 	// f, err := os.Create("/tmp/pcap6")
@@ -81,7 +83,7 @@ func TestDHCPv6(t *testing.T) {
 
 	duid := []byte{0x00, 0x0a, 0x00, 0x03, 0x00, 0x01, 0x4c, 0x5e, 0xc, 0x41, 0xbf, 0x39}
 	c, err := dhcp6.NewClient(dhcp6.ClientConfig{
-		InterfaceName: "veth0a",
+		InterfaceName: "veth1a",
 		DUID:          duid,
 	})
 	if err != nil {
@@ -105,11 +107,11 @@ func TestDHCPv6(t *testing.T) {
 		dnsmasq.Kill() // flush log
 		got := dnsmasq.Actions()
 		want := []string{
-			"DHCPSOLICIT(veth0b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
-			"DHCPADVERTISE(veth0b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
-			"DHCPREQUEST(veth0b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
-			"DHCPREPLY(veth0b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
-			"DHCPRELEASE(veth0b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
+			"DHCPSOLICIT(veth1b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
+			"DHCPADVERTISE(veth1b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
+			"DHCPREQUEST(veth1b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
+			"DHCPREPLY(veth1b) 2001:db8::c 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
+			"DHCPRELEASE(veth1b) 00:0a:00:03:00:01:4c:5e:0c:41:bf:39",
 		}
 		withoutMac := func(line string) string {
 			return v6AddrRe.ReplaceAllString(strings.TrimSpace(line), "")
diff --git a/internal/testing/dnsmasq/dnsmasq.go b/internal/testing/dnsmasq/dnsmasq.go
index ae561e4..7c92957 100644
--- a/internal/testing/dnsmasq/dnsmasq.go
+++ b/internal/testing/dnsmasq/dnsmasq.go
@@ -30,7 +30,7 @@ type Process struct {
 var dhcpActionRe = regexp.MustCompile(` (DHCP[^(]+\(.*)$`)
 
 // Run starts a dnsmasq(8) process and returns a handle to it.
-func Run(t *testing.T, args ...string) *Process {
+func Run(t *testing.T, iface string) *Process {
 	const ns = "ns0" // TODO: configurable?
 
 	ready, err := ioutil.TempFile("", "router7")
@@ -54,9 +54,9 @@ func Run(t *testing.T, args ...string) *Process {
 		"--log-facility=-",     // log to stderr
 		"--pid-file="+ready.Name(),
 		"--bind-interfaces",
-		"--interface=veth0b",
+		"--interface="+iface,
 		"--dhcp-range=192.168.23.2,192.168.23.10",
-		"--dhcp-range=::1,::10,constructor:veth0b",
+		"--dhcp-range=::1,::10,constructor:"+iface,
 		"--dhcp-authoritative", // eliminate timeouts
 		"--no-ping",            // disable ICMP confirmation of unused addresses to eliminate tedious timeout
 		"--leasefile-ro",       // do not create a lease database
diff --git a/internal/testing/dnsmasq/example_test.go b/internal/testing/dnsmasq/example_test.go
index 4760ae5..50407b3 100644
--- a/internal/testing/dnsmasq/example_test.go
+++ b/internal/testing/dnsmasq/example_test.go
@@ -9,7 +9,7 @@ import (
 )
 
 func Example(t *testing.T) {
-	dnsmasq := dnsmasq.Run(t)
+	dnsmasq := dnsmasq.Run(t, "veth0b")
 	defer dnsmasq.Kill()
 	// test code here