diff --git a/src/drivers/net/ipoib.c b/src/drivers/net/ipoib.c
index 9c9bc918..47090bb2 100644
--- a/src/drivers/net/ipoib.c
+++ b/src/drivers/net/ipoib.c
@@ -222,6 +222,21 @@ const char * ipoib_ntoa ( const void *ll_addr ) {
 	return buf;
 }
 
+/**
+ * Hash multicast address
+ *
+ * @v af		Address family
+ * @v net_addr		Network-layer address
+ * @v ll_addr		Link-layer address to fill in
+ * @ret rc		Return status code
+ */
+static int ipoib_mc_hash ( unsigned int af __unused,
+			   const void *net_addr __unused,
+			   void *ll_addr __unused ) {
+
+	return -ENOTSUP;
+}
+
 /** IPoIB protocol */
 struct ll_protocol ipoib_protocol __ll_protocol = {
 	.name		= "IPoIB",
@@ -232,6 +247,7 @@ struct ll_protocol ipoib_protocol __ll_protocol = {
 	.push		= ipoib_push,
 	.pull		= ipoib_pull,
 	.ntoa		= ipoib_ntoa,
+	.mc_hash	= ipoib_mc_hash,
 };
 
 /****************************************************************************
diff --git a/src/include/gpxe/netdevice.h b/src/include/gpxe/netdevice.h
index 9f39e0c9..3109db83 100644
--- a/src/include/gpxe/netdevice.h
+++ b/src/include/gpxe/netdevice.h
@@ -120,6 +120,16 @@ struct ll_protocol {
 	 * allocated.
 	 */
 	const char * ( * ntoa ) ( const void * ll_addr );
+	/**
+	 * Hash multicast address
+	 *
+	 * @v af	Address family
+	 * @v net_addr	Network-layer address
+	 * @v ll_addr	Link-layer address to fill in
+	 * @ret rc	Return status code
+	 */
+	int ( * mc_hash ) ( unsigned int af, const void *net_addr,
+			    void *ll_addr );
 	/** Link-layer protocol
 	 *
 	 * This is an ARPHRD_XXX constant, in network byte order.
diff --git a/src/net/ethernet.c b/src/net/ethernet.c
index 7b1c496f..ebb551f0 100644
--- a/src/net/ethernet.c
+++ b/src/net/ethernet.c
@@ -24,6 +24,7 @@
 #include <assert.h>
 #include <gpxe/if_arp.h>
 #include <gpxe/if_ether.h>
+#include <gpxe/in.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/iobuf.h>
 #include <gpxe/ethernet.h>
@@ -92,8 +93,8 @@ static int eth_pull ( struct io_buffer *iobuf,
 /**
  * Transcribe Ethernet address
  *
- * @v ll_addr	Link-layer address
- * @ret string	Link-layer address in human-readable format
+ * @v ll_addr		Link-layer address
+ * @ret string		Link-layer address in human-readable format
  */
 const char * eth_ntoa ( const void *ll_addr ) {
 	static char buf[18]; /* "00:00:00:00:00:00" */
@@ -105,6 +106,32 @@ const char * eth_ntoa ( const void *ll_addr ) {
 	return buf;
 }
 
+/**
+ * Hash multicast address
+ *
+ * @v af		Address family
+ * @v net_addr		Network-layer address
+ * @v ll_addr		Link-layer address to fill in
+ * @ret rc		Return status code
+ */
+static int eth_mc_hash ( unsigned int af, const void *net_addr,
+			 void *ll_addr ) {
+	const uint8_t *net_addr_bytes = net_addr;
+	uint8_t *ll_addr_bytes = ll_addr;
+
+	switch ( af ) {
+	case AF_INET:
+		ll_addr_bytes[0] = 0x01;
+		ll_addr_bytes[1] = 0x00;
+		ll_addr_bytes[2] = 0x5e;
+		ll_addr_bytes[3] = net_addr_bytes[1] & 0x7f;
+		ll_addr_bytes[4] = net_addr_bytes[2];
+		ll_addr_bytes[5] = net_addr_bytes[3];
+	default:
+		return -ENOTSUP;
+	}
+}
+
 /** Ethernet protocol */
 struct ll_protocol ethernet_protocol __ll_protocol = {
 	.name		= "Ethernet",
@@ -115,4 +142,5 @@ struct ll_protocol ethernet_protocol __ll_protocol = {
 	.push		= eth_push,
 	.pull		= eth_pull,
 	.ntoa		= eth_ntoa,
+	.mc_hash	= eth_mc_hash,
 };
diff --git a/src/net/ipv4.c b/src/net/ipv4.c
index 82a13c33..e14ed6a7 100644
--- a/src/net/ipv4.c
+++ b/src/net/ipv4.c
@@ -266,7 +266,6 @@ static uint16_t ipv4_pshdr_chksum ( struct io_buffer *iobuf, uint16_t csum ) {
 static int ipv4_ll_addr ( struct in_addr dest, struct in_addr src,
 			  struct net_device *netdev, uint8_t *ll_dest ) {
 	struct ll_protocol *ll_protocol = netdev->ll_protocol;
-	uint8_t *dest_bytes = ( ( uint8_t * ) &dest );
 
 	if ( dest.s_addr == INADDR_BROADCAST ) {
 		/* Broadcast address */
@@ -274,17 +273,7 @@ static int ipv4_ll_addr ( struct in_addr dest, struct in_addr src,
 			 ll_protocol->ll_addr_len );
 		return 0;
 	} else if ( IN_MULTICAST ( ntohl ( dest.s_addr ) ) ) {
-		/* Special case: IPv4 multicast over Ethernet.	This
-		 * code may need to be generalised once we find out
-		 * what happens for other link layers.
-		 */
-		ll_dest[0] = 0x01;
-		ll_dest[1] = 0x00;
-		ll_dest[2] = 0x5e;
-		ll_dest[3] = dest_bytes[1] & 0x7f;
-		ll_dest[4] = dest_bytes[2];
-		ll_dest[5] = dest_bytes[3];
-		return 0;
+		return ll_protocol->mc_hash ( AF_INET, &dest, ll_dest );
 	} else {
 		/* Unicast address: resolve via ARP */
 		return arp_resolve ( netdev, &ipv4_protocol, &dest,