diff --git a/arch/sandbox/cpu/eth-raw-os.c b/arch/sandbox/cpu/eth-raw-os.c
index 4263d88..82bf666 100644
--- a/arch/sandbox/cpu/eth-raw-os.c
+++ b/arch/sandbox/cpu/eth-raw-os.c
@@ -25,8 +25,8 @@
 #include <linux/if_ether.h>
 #include <linux/if_packet.h>
 
-static int _raw_packet_start(const char *ifname, unsigned char *ethmac,
-			    struct eth_sandbox_raw_priv *priv)
+static int _raw_packet_start(struct eth_sandbox_raw_priv *priv,
+			     unsigned char *ethmac)
 {
 	struct sockaddr_ll *device;
 	struct packet_mreq mr;
@@ -40,7 +40,8 @@
 		return -ENOMEM;
 	device = priv->device;
 	memset(device, 0, sizeof(struct sockaddr_ll));
-	device->sll_ifindex = if_nametoindex(ifname);
+	device->sll_ifindex = if_nametoindex(priv->host_ifname);
+	priv->host_ifindex = device->sll_ifindex;
 	device->sll_family = AF_PACKET;
 	memcpy(device->sll_addr, ethmac, 6);
 	device->sll_halen = htons(6);
@@ -53,11 +54,11 @@
 		return -errno;
 	}
 	/* Bind to the specified interface */
-	ret = setsockopt(priv->sd, SOL_SOCKET, SO_BINDTODEVICE, ifname,
-		   strlen(ifname) + 1);
+	ret = setsockopt(priv->sd, SOL_SOCKET, SO_BINDTODEVICE,
+			 priv->host_ifname, strlen(priv->host_ifname) + 1);
 	if (ret < 0) {
-		printf("Failed to bind to '%s': %d %s\n", ifname, errno,
-		       strerror(errno));
+		printf("Failed to bind to '%s': %d %s\n", priv->host_ifname,
+		       errno, strerror(errno));
 		return -errno;
 	}
 
@@ -76,11 +77,12 @@
 		printf("Failed to set promiscuous mode: %d %s\n"
 		       "Falling back to the old \"flags\" way...\n",
 			errno, strerror(errno));
-		if (strlen(ifname) >= IFNAMSIZ) {
-			printf("Interface name %s is too long.\n", ifname);
+		if (strlen(priv->host_ifname) >= IFNAMSIZ) {
+			printf("Interface name %s is too long.\n",
+			       priv->host_ifname);
 			return -EINVAL;
 		}
-		strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+		strncpy(ifr.ifr_name, priv->host_ifname, IFNAMSIZ);
 		if (ioctl(priv->sd, SIOCGIFFLAGS, &ifr) < 0) {
 			printf("Failed to read flags: %d %s\n", errno,
 			       strerror(errno));
@@ -142,13 +144,13 @@
 	return 0;
 }
 
-int sandbox_eth_raw_os_start(const char *ifname, unsigned char *ethmac,
-			    struct eth_sandbox_raw_priv *priv)
+int sandbox_eth_raw_os_start(struct eth_sandbox_raw_priv *priv,
+			     unsigned char *ethmac)
 {
 	if (priv->local)
 		return _local_inet_start(priv);
 	else
-		return _raw_packet_start(ifname, ethmac, priv);
+		return _raw_packet_start(priv, ethmac);
 }
 
 int sandbox_eth_raw_os_send(void *packet, int length,
diff --git a/arch/sandbox/include/asm/eth-raw-os.h b/arch/sandbox/include/asm/eth-raw-os.h
index f986d31..760f5fb 100644
--- a/arch/sandbox/include/asm/eth-raw-os.h
+++ b/arch/sandbox/include/asm/eth-raw-os.h
@@ -9,10 +9,14 @@
 #ifndef __ETH_RAW_OS_H
 #define __ETH_RAW_OS_H
 
+#define	IFNAMSIZ	16
+
 /**
  * struct eth_sandbox_raw_priv - raw socket session
  *
  * sd: socket descriptor - the open socket during a session
+ * host_ifname: interface name on the host to use for sending our packets
+ * host_ifindex: interface index number on the host
  * device: struct sockaddr_ll - the host interface packets move to/from
  * local: 1 or 0 to select the local interface ('lo') or not
  * local_bindsd: socket descriptor to prevent the kernel from sending
@@ -22,14 +26,16 @@
  */
 struct eth_sandbox_raw_priv {
 	int sd;
+	char host_ifname[IFNAMSIZ];
+	unsigned int host_ifindex;
 	void *device;
 	int local;
 	int local_bind_sd;
 	unsigned short local_bind_udp_port;
 };
 
-int sandbox_eth_raw_os_start(const char *ifname, unsigned char *ethmac,
-			    struct eth_sandbox_raw_priv *priv);
+int sandbox_eth_raw_os_start(struct eth_sandbox_raw_priv *priv,
+			     unsigned char *ethmac);
 int sandbox_eth_raw_os_send(void *packet, int length,
 			    struct eth_sandbox_raw_priv *priv);
 int sandbox_eth_raw_os_recv(void *packet, int *length,