diff --git a/BaS_gcc/include/ip.h b/BaS_gcc/include/ip.h
index 9b3d562..ece30b5 100644
--- a/BaS_gcc/include/ip.h
+++ b/BaS_gcc/include/ip.h
@@ -1,100 +1,83 @@
-/*
- * File:        ip.h
- * Purpose:     Definitions for the Internet Protocol, IP.
- *
- * Notes:       See RFC 791 "DARPA Internet Program Protocol
- *              Specification" for more details.
- */
-
-#ifndef _IP_H
-#define _IP_H
-
-/********************************************************************/
-
-/* 32-bit IP Addresses */
-typedef uint8_t IP_ADDR[4];
-
-/* Pointer to an IP Address */
-typedef uint8_t IP_ADDR_P[];
-
-/* Definition of an IP packet header */
-typedef struct
-{
-    uint8_t       version_ihl;
-    uint8_t       service_type;
-    uint16_t      total_length;
-    uint16_t      identification;
-    uint16_t      flags_frag_offset;
-    uint8_t       ttl;
-    uint8_t       protocol;
-    uint16_t      checksum;
-    IP_ADDR     source_addr;
-    IP_ADDR     dest_addr;
-    uint8_t       options;    /* actually an array of undetermined length */
-} ip_frame_hdr;
-
-/* Macros for accessing an IP datagram.  */
-#define IP_VERSION(a)   ((a->version_ihl & 0x00F0) >> 4)
-#define IP_IHL(a)       ((a->version_ihl & 0x000F))
-#define IP_SERVICE(a)   (a->service_type)
-#define IP_LENGTH(a)    (a->total_length)
-#define IP_IDENT(a)     (a->identification)
-#define IP_FLAGS(a)     ((a->flags_frag_offset & 0x0000E000) >> 13)
-#define IP_FRAGMENT(a)  ((a->flags_frag_offset & 0x00001FFF))
-#define IP_TTL(a)       (a->ttl)
-#define IP_PROTOCOL(a)  (a->protocol)
-#define IP_CHKSUM(a)    (a->checksum)
-#define IP_SRC(a)       (&a->source_addr[0])
-#define IP_DEST(a)      (&a->dest_addr[0])
-#define IP_OPTIONS(a)   (&a->options)
-#define IP_DATA(a)      (&((uint8_t *)a)[IP_IHL(a) * 4])
-
-/* Defined IP protocols */
-#define IP_PROTO_ICMP   (1)
-#define IP_PROTO_UDP    (17)
-
-/* Protocol Header information */
-#define IP_HDR_OFFSET   ETH_HDR_LEN
-#define IP_HDR_SIZE     20  /* no options */
-
-/********************************************************************/
-
-typedef struct
-{
-    IP_ADDR         myip;
-    IP_ADDR         gateway;
-    IP_ADDR         netmask;
-    IP_ADDR         broadcast;
-    unsigned int    rx;
-    unsigned int    rx_unsup;
-    unsigned int    tx;
-    unsigned int    err;
-} IP_INFO;
-
-/********************************************************************/
-
-void
-ip_handler (NIF *, NBUF *);
-
-uint16_t
-ip_chksum (uint16_t *, int);
-
-int
-ip_send (NIF *, 
-        uint8_t *,    /* destination IP */
-        uint8_t *,    /* source IP */
-        uint8_t,      /* protocol */
-        NBUF *      /* buffer descriptor */);
-
-void
-ip_init (IP_INFO *, IP_ADDR_P, IP_ADDR_P, IP_ADDR_P);
-
-uint8_t *
-ip_get_myip (IP_INFO *);
-
-uint8_t *
-ip_resolve_route (NIF *, IP_ADDR_P);
-
-/********************************************************************/
-
-#endif  /* _IP_H */
+/*
+ * File:        ip.h
+ * Purpose:     Definitions for the Internet Protocol, IP.
+ *
+ * Notes:       See RFC 791 "DARPA Internet Program Protocol
+ *              Specification" for more details.
+ */
+
+#ifndef _IP_H
+#define _IP_H
+
+/********************************************************************/
+
+/* 32-bit IP Addresses */
+typedef uint8_t IP_ADDR[4];
+
+/* Pointer to an IP Address */
+typedef uint8_t IP_ADDR_P[];
+
+/* Definition of an IP packet header */
+typedef struct
+{
+	uint8_t       version_ihl;
+	uint8_t       service_type;
+	uint16_t      total_length;
+	uint16_t      identification;
+	uint16_t      flags_frag_offset;
+	uint8_t       ttl;
+	uint8_t       protocol;
+	uint16_t      checksum;
+	IP_ADDR     source_addr;
+	IP_ADDR     dest_addr;
+	uint8_t       options;    /* actually an array of undetermined length */
+} ip_frame_hdr;
+
+/* Macros for accessing an IP datagram.  */
+#define IP_VERSION(a)   ((a->version_ihl & 0x00F0) >> 4)
+#define IP_IHL(a)       ((a->version_ihl & 0x000F))
+#define IP_SERVICE(a)   (a->service_type)
+#define IP_LENGTH(a)    (a->total_length)
+#define IP_IDENT(a)     (a->identification)
+#define IP_FLAGS(a)     ((a->flags_frag_offset & 0x0000E000) >> 13)
+#define IP_FRAGMENT(a)  ((a->flags_frag_offset & 0x00001FFF))
+#define IP_TTL(a)       (a->ttl)
+#define IP_PROTOCOL(a)  (a->protocol)
+#define IP_CHKSUM(a)    (a->checksum)
+#define IP_SRC(a)       (&a->source_addr[0])
+#define IP_DEST(a)      (&a->dest_addr[0])
+#define IP_OPTIONS(a)   (&a->options)
+#define IP_DATA(a)      (&((uint8_t *)a)[IP_IHL(a) * 4])
+
+/* Defined IP protocols */
+#define IP_PROTO_ICMP   (1)
+#define IP_PROTO_UDP    (17)
+
+/* Protocol Header information */
+#define IP_HDR_OFFSET   ETH_HDR_LEN
+#define IP_HDR_SIZE     20  /* no options */
+
+/********************************************************************/
+
+typedef struct
+{
+	IP_ADDR         myip;
+	IP_ADDR         gateway;
+	IP_ADDR         netmask;
+	IP_ADDR         broadcast;
+	unsigned int    rx;
+	unsigned int    rx_unsup;
+	unsigned int    tx;
+	unsigned int    err;
+} IP_INFO;
+
+/********************************************************************/
+
+extern void ip_handler(NIF *nif, NBUF *nbf);
+uint16_t ip_chksum(uint16_t *data, int num);
+extern int ip_send(NIF *nif, uint8_t *dest_addr, uint8_t *src_addr, uint8_t protocol, NBUF *nbf);
+extern void ip_init(IP_INFO *, IP_ADDR_P, IP_ADDR_P, IP_ADDR_P);
+extern uint8_t *ip_get_myip(IP_INFO *);
+extern uint8_t *ip_resolve_route(NIF *, IP_ADDR_P);
+
+#endif  /* _IP_H */
diff --git a/BaS_gcc/net/bootp.c b/BaS_gcc/net/bootp.c
index f7e0b1a..3858299 100644
--- a/BaS_gcc/net/bootp.c
+++ b/BaS_gcc/net/bootp.c
@@ -50,6 +50,7 @@ void bootp_request(NIF *nif, uint8_t *pa)
 	p->yi_addr = 0x0;
 	p->gi_addr = 0x0;
 
+	connection.nif = nif;
 	addr = &nif->hwa[0];
 	for (i = 0; i < 6; i++)
 		p->ch_addr[i] = addr[i];
diff --git a/BaS_gcc/net/ip.c b/BaS_gcc/net/ip.c
index 0c2ae8e..bc0e7d5 100644
--- a/BaS_gcc/net/ip.c
+++ b/BaS_gcc/net/ip.c
@@ -11,284 +11,303 @@
 #include <stddef.h>
 
 
+#define IP_DEBUG
+#if defined(IP_DEBUG)
+#define dbg(format, arg...) do { xprintf("DEBUG: " format "\r\n", ##arg); } while (0)
+#else
+#define dbg(format, arg...) do { ; } while (0)
+#endif
+
 void ip_init(IP_INFO *info, IP_ADDR_P myip, IP_ADDR_P gateway, IP_ADDR_P netmask)
 {
-    int index;
+	int index;
 
-    for (index = 0; index < sizeof(IP_ADDR); index++)
-    {
-        info->myip[index] = myip[index];
-        info->gateway[index] = gateway[index];
-        info->netmask[index] = netmask[index];
-        info->broadcast[index] = 0xFF;
-    }
+	for (index = 0; index < sizeof(IP_ADDR); index++)
+	{
+		info->myip[index] = myip[index];
+		info->gateway[index] = gateway[index];
+		info->netmask[index] = netmask[index];
+		info->broadcast[index] = 0xFF;
+	}
 
-    info->rx = 0;
-    info->rx_unsup = 0;
-    info->tx = 0;
-    info->err = 0;
+	info->rx = 0;
+	info->rx_unsup = 0;
+	info->tx = 0;
+	info->err = 0;
 }
 
 uint8_t *ip_get_myip(IP_INFO *info)
 {
-    if (info != 0)
-    {
-        return (uint8_t *) &info->myip[0];
-    }
-    return 0;
+	if (info != 0)
+	{
+		return (uint8_t *) &info->myip[0];
+	}
+	dbg("%s: info is NULL!\n\t", __FUNCTION__);
+	return 0;
 }
 
 int ip_addr_compare(IP_ADDR_P addr1, IP_ADDR_P addr2)
 {
-    int i;
+	int i;
 
-    for (i = 0; i < sizeof(IP_ADDR); i++)
-    {
-        if (addr1[i] != addr2[i])
-            return 0;
-    }
-    return 1;
+	for (i = 0; i < sizeof(IP_ADDR); i++)
+	{
+		if (addr1[i] != addr2[i])
+			return 0;
+	}
+	return 1;
 }
 
 uint8_t *ip_resolve_route(NIF *nif, IP_ADDR_P destip)
 {
-    /*
-     * This function determines whether or not an outgoing IP
-     * packet needs to be transmitted on the local net or sent
-     * to the router for transmission.
-     */
-    IP_INFO *info;
-    IP_ADDR mask, result;
-    int i;
+	/*
+	 * This function determines whether or not an outgoing IP
+	 * packet needs to be transmitted on the local net or sent
+	 * to the router for transmission.
+	 */
+	IP_INFO *info;
+	IP_ADDR mask, result;
+	IP_ADDR bc = { 255, 255, 255, 255 };
+	int i;
 
-    info = nif_get_protocol_info(nif, ETH_FRM_IP);
+	info = nif_get_protocol_info(nif, ETH_FRM_IP);
 
-    /* create mask for local IP */
-    for (i = 0; i < sizeof(IP_ADDR); i++)
-    {
-        mask[i] = info->myip[i] & info->netmask[i];
-    }
+	if (memcmp(destip, bc) == 0)
+	{
+		dbg("%s: destip is broadcast address, no gateway needed\r\n", __FUNCTION__);
+		return destip;
+	}
 
-    /* apply mask to the destination IP */
-    for (i = 0; i < sizeof(IP_ADDR); i++)
-    {
-        result[i] = mask[i] & destip[i];
-    }
+	/* create mask for local IP */
+	for (i = 0; i < sizeof(IP_ADDR); i++)
+	{
+		mask[i] = info->myip[i] & info->netmask[i];
+	}
 
-    /* See if destination IP is local or not */
-    if (ip_addr_compare(mask, result))
-    {
-        /* The destination IP is on the local net */
-        return arp_resolve(nif, ETH_FRM_IP, destip);
-    }
-    else
-    {
-        /* The destination IP is not on the local net */
-        return arp_resolve(nif, ETH_FRM_IP, info->gateway);
-    }
+	/* apply mask to the destination IP */
+	for (i = 0; i < sizeof(IP_ADDR); i++)
+	{
+		result[i] = mask[i] & destip[i];
+	}
+
+	/* See if destination IP is local or not */
+	if (ip_addr_compare(mask, result))
+	{
+		/* The destination IP is on the local net */
+		return arp_resolve(nif, ETH_FRM_IP, destip);
+	}
+	else
+	{
+		/* The destination IP is not on the local net */
+		return arp_resolve(nif, ETH_FRM_IP, info->gateway);
+	}
 }
 
 int ip_send(NIF *nif, uint8_t *dest, uint8_t *src, uint8_t protocol, NBUF *pNbuf)
 {
-    /*
-     * This function assembles an IP datagram and passes it
-     * onto the hardware to be sent over the network.
-     */
-    uint8_t *route;
-    ip_frame_hdr *ipframe;
+	/*
+	 * This function assembles an IP datagram and passes it
+	 * onto the hardware to be sent over the network.
+	 */
+	uint8_t *route;
+	ip_frame_hdr *ipframe;
 
-    /*
-     * Construct the IP header
-     */
-    ipframe = (ip_frame_hdr*) &pNbuf->data[IP_HDR_OFFSET];
+	/*
+	 * Construct the IP header
+	 */
+	ipframe = (ip_frame_hdr*) &pNbuf->data[IP_HDR_OFFSET];
 
-    /* IP version 4, Internet Header Length of 5 32-bit words */
-    ipframe->version_ihl = 0x45;
+	/* IP version 4, Internet Header Length of 5 32-bit words */
+	ipframe->version_ihl = 0x45;
 
-    /* Type of Service == 0, normal and routine */
-    ipframe->service_type = 0x00;
+	/* Type of Service == 0, normal and routine */
+	ipframe->service_type = 0x00;
 
-    /* Total length of data */
-    ipframe->total_length = (uint16_t) (pNbuf->length + IP_HDR_SIZE);
+	/* Total length of data */
+	ipframe->total_length = (uint16_t) (pNbuf->length + IP_HDR_SIZE);
 
-    /* User defined identification */
-    ipframe->identification = 0x0000;
+	/* User defined identification */
+	ipframe->identification = 0x0000;
 
-    /* Fragment Flags and Offset -- Don't fragment, last frag */
-    ipframe->flags_frag_offset = 0x0000;
+	/* Fragment Flags and Offset -- Don't fragment, last frag */
+	ipframe->flags_frag_offset = 0x0000;
 
-    /* Time To Live */
-    ipframe->ttl = 0xFF;
+	/* Time To Live */
+	ipframe->ttl = 0xFF;
 
-    /* Protocol */
-    ipframe->protocol = protocol;
+	/* Protocol */
+	ipframe->protocol = protocol;
 
-    /* Checksum, computed later, zeroed for computation */
-    ipframe->checksum = 0x0000;
+	/* Checksum, computed later, zeroed for computation */
+	ipframe->checksum = 0x0000;
 
-    /* source IP address */
-    ipframe->source_addr[0] = src[0];
-    ipframe->source_addr[1] = src[1];
-    ipframe->source_addr[2] = src[2];
-    ipframe->source_addr[3] = src[3];
+	/* source IP address */
+	ipframe->source_addr[0] = src[0];
+	ipframe->source_addr[1] = src[1];
+	ipframe->source_addr[2] = src[2];
+	ipframe->source_addr[3] = src[3];
 
-    /* dest IP address */
-    ipframe->dest_addr[0] = dest[0];
-    ipframe->dest_addr[1] = dest[1];
-    ipframe->dest_addr[2] = dest[2];
-    ipframe->dest_addr[3] = dest[3];
+	/* dest IP address */
+	ipframe->dest_addr[0] = dest[0];
+	ipframe->dest_addr[1] = dest[1];
+	ipframe->dest_addr[2] = dest[2];
+	ipframe->dest_addr[3] = dest[3];
 
-    /* Compute checksum */
-    ipframe->checksum = ip_chksum((uint16_t *) ipframe, IP_HDR_SIZE);
+	/* Compute checksum */
+	ipframe->checksum = ip_chksum((uint16_t *) ipframe, IP_HDR_SIZE);
 
-    /* Increment the packet length by the size of the IP header */
-    pNbuf->length += IP_HDR_SIZE;
+	/* Increment the packet length by the size of the IP header */
+	pNbuf->length += IP_HDR_SIZE;
 
-    /*
-     * Determine the hardware address of the recipient
-     */
+	/*
+	 * Determine the hardware address of the recipient
+	 */
 	IP_ADDR bc = { 255, 255, 255, 255};
 	if (memcmp(bc, dest, 4) != 0)
 	{
 		route = ip_resolve_route(nif, dest);
 		if (route == NULL)
 		{
-			xprintf("Unable to locate %d.%d.%d.%d\n",
-				dest[0], dest[1], dest[2], dest[3]);
+			dbg("Unable to locate %d.%d.%d.%d\n",
+					dest[0], dest[1], dest[2], dest[3]);
 			return 0;
 		}
 	}
 	else
+	{
 		route = bc;
+		dbg("%s: route = broadcast\r\n", __FUNCTION__);
+		dbg("%s: nif = %p\r\n", __FUNCTION__, nif);
+		dbg("%s: nif->send = %p\n\t", __FUNCTION__, nif->send);
+	}
 
-    return nif->send(nif, route, &nif->hwa[0], ETH_FRM_IP, pNbuf);
+	return nif->send(nif, route, &nif->hwa[0], ETH_FRM_IP, pNbuf);
 }
 
 #if defined(DEBUG_PRINT)
-void
-dump_ip_frame (ip_frame_hdr *ipframe)
+void dump_ip_frame(ip_frame_hdr *ipframe)
 {
-    printf("Version:  %02X\n", ((ipframe->version_ihl & 0x00f0) >> 4));
-    printf("IHL:      %02X\n", ipframe->version_ihl & 0x000f);
-    printf("Service:  %02X\n", ipframe->service_type);
-    printf("Length:   %04X\n", ipframe->total_length);
-    printf("Ident:    %04X\n", ipframe->identification);
-    printf("Flags:    %02X\n", ((ipframe->flags_frag_offset & 0xC000) >> 14));
-    printf("Frag:     %04X\n", ipframe->flags_frag_offset & 0x3FFF);
-    printf("TTL:      %02X\n", ipframe->ttl);
-    printf("Protocol: %02X\n", ipframe->protocol);
-    printf("Chksum:   %04X\n", ipframe->checksum);
-    printf("Source  : %d.%d.%d.%d\n",
-        ipframe->source_addr[0],
-        ipframe->source_addr[1],
-        ipframe->source_addr[2],
-        ipframe->source_addr[3]);
-    printf("Dest    : %d.%d.%d.%d\n",
-        ipframe->dest_addr[0],
-        ipframe->dest_addr[1],
-        ipframe->dest_addr[2],
-        ipframe->dest_addr[3]);
-    printf("Options: %08X\n", ipframe->options);
+	xprintf("Version:  %02X\n", ((ipframe->version_ihl & 0x00f0) >> 4));
+	xprintf("IHL:      %02X\n", ipframe->version_ihl & 0x000f);
+	xprintf("Service:  %02X\n", ipframe->service_type);
+	xprintf("Length:   %04X\n", ipframe->total_length);
+	xprintf("Ident:    %04X\n", ipframe->identification);
+	xprintf("Flags:    %02X\n", ((ipframe->flags_frag_offset & 0xC000) >> 14));
+	xprintf("Frag:     %04X\n", ipframe->flags_frag_offset & 0x3FFF);
+	xprintf("TTL:      %02X\n", ipframe->ttl);
+	xprintf("Protocol: %02X\n", ipframe->protocol);
+	xprintf("Chksum:   %04X\n", ipframe->checksum);
+	xprintf("Source  : %d.%d.%d.%d\n",
+			ipframe->source_addr[0],
+			ipframe->source_addr[1],
+			ipframe->source_addr[2],
+			ipframe->source_addr[3]);
+	xprintf("Dest    : %d.%d.%d.%d\n",
+			ipframe->dest_addr[0],
+			ipframe->dest_addr[1],
+			ipframe->dest_addr[2],
+			ipframe->dest_addr[3]);
+	xprintf("Options: %08X\n", ipframe->options);
 }
 #endif
 
 
 uint16_t ip_chksum(uint16_t *data, int num)
 {
-    int chksum, ichksum;
-    uint16_t temp;
+	int chksum, ichksum;
+	uint16_t temp;
 
-    chksum = 0;
-    num = num >> 1; /* from bytes to words */
-    for (; num; num--, data++)
-    {
-        temp = *data;
-        ichksum = chksum + temp;
-        ichksum = ichksum & 0x0000FFFF;
-        if ((ichksum < temp) || (ichksum < chksum))
-        {
-            ichksum += 1;
-            ichksum = ichksum & 0x0000FFFF;
-        }
-        chksum = ichksum;
-    }
-    return (uint16_t) ~chksum;
+	chksum = 0;
+	num = num >> 1; /* from bytes to words */
+	for (; num; num--, data++)
+	{
+		temp = *data;
+		ichksum = chksum + temp;
+		ichksum = ichksum & 0x0000FFFF;
+		if ((ichksum < temp) || (ichksum < chksum))
+		{
+			ichksum += 1;
+			ichksum = ichksum & 0x0000FFFF;
+		}
+		chksum = ichksum;
+	}
+	return (uint16_t) ~chksum;
 }
 
 static int validate_ip_hdr(NIF *nif, ip_frame_hdr *ipframe)
 {
-    int index, chksum;
-    IP_INFO *info;
+	int index, chksum;
+	IP_INFO *info;
 
-    /*
-     * Check the IP Version
-     */
-    if (IP_VERSION(ipframe) != 4)
-        return 0;
+	/*
+	 * Check the IP Version
+	 */
+	if (IP_VERSION(ipframe) != 4)
+		return 0;
 
-    /*
-     * Check Internet Header Length
-     */
-    if (IP_IHL(ipframe) < 5)
-        return 0;
+	/*
+	 * Check Internet Header Length
+	 */
+	if (IP_IHL(ipframe) < 5)
+		return 0;
 
-    /*
-     * Check the destination IP address
-     */
-    info = nif_get_protocol_info(nif,ETH_FRM_IP);
-    for (index = 0; index < sizeof(IP_ADDR); index++)
-        if (info->myip[index] != ipframe->dest_addr[index])
-            return 0;
+	/*
+	 * Check the destination IP address
+	 */
+	info = nif_get_protocol_info(nif,ETH_FRM_IP);
+	for (index = 0; index < sizeof(IP_ADDR); index++)
+		if (info->myip[index] != ipframe->dest_addr[index])
+			return 0;
 
-    /*
-     * Check the checksum
-     */
-    chksum = (int)((uint16_t) IP_CHKSUM(ipframe));
-    IP_CHKSUM(ipframe) = 0;
+	/*
+	 * Check the checksum
+	 */
+	chksum = (int)((uint16_t) IP_CHKSUM(ipframe));
+	IP_CHKSUM(ipframe) = 0;
 
-    if (ip_chksum((uint16_t *) ipframe, IP_IHL(ipframe) * 4) != chksum)
-        return 0;
+	if (ip_chksum((uint16_t *) ipframe, IP_IHL(ipframe) * 4) != chksum)
+		return 0;
 
-    IP_CHKSUM(ipframe) = (uint16_t) chksum;
+	IP_CHKSUM(ipframe) = (uint16_t) chksum;
 
-    return 1;
+	return 1;
 }
 
 void ip_handler(NIF *nif, NBUF *pNbuf)
 {
-    /*
-     * IP packet handler
-     */
-    ip_frame_hdr *ipframe;
+	/*
+	 * IP packet handler
+	 */
+	ip_frame_hdr *ipframe;
 
-    ipframe = (ip_frame_hdr *)&pNbuf->data[pNbuf->offset];
+	ipframe = (ip_frame_hdr *) &pNbuf->data[pNbuf->offset];
 
-    /*
-     * Verify valid IP header and destination IP
-     */
-    if (!validate_ip_hdr(nif, ipframe))
-    {
-        nbuf_free(pNbuf);
-        return;
-    }
+	/*
+	 * Verify valid IP header and destination IP
+	 */
+	if (!validate_ip_hdr(nif, ipframe))
+	{
+		nbuf_free(pNbuf);
+		return;
+	}
 
-    pNbuf->offset += (IP_IHL(ipframe) * 4);
-    pNbuf->length = (uint16_t)(IP_LENGTH(ipframe) - (IP_IHL(ipframe) * 4));
+	pNbuf->offset += (IP_IHL(ipframe) * 4);
+	pNbuf->length = (uint16_t)(IP_LENGTH(ipframe) - (IP_IHL(ipframe) * 4));
 
-    /*
-     * Call the appriopriate handler
-     */
-    switch (IP_PROTOCOL(ipframe))
-    {
-        case IP_PROTO_ICMP:
-            // FIXME: icmp_handler(nif,pNbuf);
-            break;
-        case IP_PROTO_UDP:
-            udp_handler(nif,pNbuf);
-            break;
-        default:
-            nbuf_free(pNbuf);
-            break;
-    }
-    return;
+	/*
+	 * Call the appriopriate handler
+	 */
+	switch (IP_PROTOCOL(ipframe))
+	{
+		case IP_PROTO_ICMP:
+			// FIXME: icmp_handler(nif,pNbuf);
+			break;
+		case IP_PROTO_UDP:
+			udp_handler(nif,pNbuf);
+			break;
+		default:
+			nbuf_free(pNbuf);
+			break;
+	}
+	return;
 }
diff --git a/BaS_gcc/net/udp.c b/BaS_gcc/net/udp.c
index 7452f24..25c9428 100644
--- a/BaS_gcc/net/udp.c
+++ b/BaS_gcc/net/udp.c
@@ -11,6 +11,13 @@
 #include "net.h"
 #include <stddef.h>
 
+#define UDP_DEBUG
+#if defined(UDP_DEBUG)
+#define dbg(format, arg...) do { xprintf("DEBUG: " format "\r\n", ##arg); } while (0)
+#else
+#define dbg(format, arg...) do { ; } while (0)
+#endif
+
 typedef struct
 {
 	uint16_t port;
@@ -99,6 +106,12 @@ uint16_t udp_obtain_free_port(void)
 
 int udp_send(NIF *nif, uint8_t *dest, int sport, int dport, NBUF *pNbuf)
 {
+	if (nif == NULL)
+	{
+		dbg("%s: nif is NULL\r\n", __FUNCTION__);
+		return 0;
+	}
+
 	/*
 	 * This function takes data and creates a UDP frame and
 	 * passes it onto the IP layer