Index: sys/dev/e1000/igb_txrx.c
===================================================================
--- sys/dev/e1000/igb_txrx.c
+++ sys/dev/e1000/igb_txrx.c
@@ -178,37 +178,43 @@
 	/* Set the ether header length */
 	vlan_macip_lens |= pi->ipi_ehdrlen << E1000_ADVTXD_MACLEN_SHIFT;
 
-	switch(pi->ipi_etype) {
-	case ETHERTYPE_IP:
-		type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_IPV4;
-		break;
-	case ETHERTYPE_IPV6:
-		type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_IPV6;
-		break;
-	default:
-		offload = FALSE;
-		break;
+	if (pi->ipi_csum_flags & CSUM_IP) {
+		switch(pi->ipi_etype) {
+		case ETHERTYPE_IP:
+			type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_IPV4;
+			break;
+		case ETHERTYPE_IPV6:
+			type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_IPV6;
+			break;
+		default:
+			offload = FALSE;
+			break;
+		}
 	}
+	else
+		offload = FALSE;
 
 	vlan_macip_lens |= pi->ipi_ip_hlen;
 	type_tucmd_mlhl |= E1000_ADVTXD_DCMD_DEXT | E1000_ADVTXD_DTYP_CTXT;
 
-	switch (pi->ipi_ipproto) {
-	case IPPROTO_TCP:
-		if (pi->ipi_csum_flags & (CSUM_IP_TCP | CSUM_IP6_TCP))
-			type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_TCP;
-		break;
-	case IPPROTO_UDP:
-		if (pi->ipi_csum_flags & (CSUM_IP_UDP | CSUM_IP6_UDP))
-			type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_UDP;
-		break;
-	case IPPROTO_SCTP:
-		if (pi->ipi_csum_flags & (CSUM_IP_SCTP | CSUM_IP6_SCTP))
-			type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_SCTP;
-		break;
-	default:
-		offload = FALSE;
-		break;
+	if (offload) {
+		switch (pi->ipi_ipproto) {
+		case IPPROTO_TCP:
+			if (pi->ipi_csum_flags & (CSUM_IP_TCP | CSUM_IP6_TCP))
+				type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_TCP;
+			break;
+		case IPPROTO_UDP:
+			if (pi->ipi_csum_flags & (CSUM_IP_UDP | CSUM_IP6_UDP))
+				type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_UDP;
+			break;
+		case IPPROTO_SCTP:
+			if (pi->ipi_csum_flags & (CSUM_IP_SCTP | CSUM_IP6_SCTP))
+				type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_SCTP;
+			break;
+		default:
+			offload = FALSE;
+			break;
+		}
 	}
 
 	if (offload) /* For the TX descriptor setup */