diff --git a/src/common/network/dhcp.c b/src/common/network/dhcp.c
index 7f47f9f..9d4f5ad 100644
--- a/src/common/network/dhcp.c
+++ b/src/common/network/dhcp.c
@@ -43,11 +43,13 @@ void DHCP_request_send(packet_t *pPacket, uint8_t dhcp_msg_type, uint8_t *mac_ad
 	// Set msg type
 	option_list_append(&options, DHCP_OPT_MSGTYPE, &dhcp_msg_type, 1);
 
-#ifdef WITH_CLIENT_ID
+	// Set vendor ID
+	const char vendor[] = "AVM multid FRITZ!Box 7362 SL (UI)";
+	option_list_append(&options, DHCP_OPT_VENDORID, vendor, strlen(vendor));
+
 	// Set client ID
 	size = data_entry_create(buffer, TYPE_HW_ETH10, mac_addr_src, 6);
 	option_list_append(&options, DHCP_OPT_CLIENTID, buffer, size);
-#endif
 
 	// Set client name
 	option_list_append(&options, DHCP_OPT_HOSTNAME, hostname, strlen(hostname));
@@ -57,6 +59,17 @@ void DHCP_request_send(packet_t *pPacket, uint8_t dhcp_msg_type, uint8_t *mac_ad
 		case DHCP_MSG_DHCPDISCOVER:
 		{
 			pDHCP->xid = (uint32_t)rand();
+
+			// Request subnet mask
+			size = 0;
+			buffer[size++] = DHCP_OPT_SUBNETMASK;
+			buffer[size++] = DHCP_OPT_ROUTER;
+			buffer[size++] = DHCP_OPT_DOMAIN_NS;
+			buffer[size++] = 121;
+			buffer[size++] = 249;
+			buffer[size++] = 42;
+			buffer[size++] = 158;
+			option_list_append(&options, DHCP_OPT_PARAM_REQ_LIST, buffer, size);
 		}
 		break;
 
@@ -76,7 +89,7 @@ void DHCP_request_send(packet_t *pPacket, uint8_t dhcp_msg_type, uint8_t *mac_ad
 	option_list_append(&options, DHCP_OPT_END, NULL, 0);
 
 	// Create packet
-	UDP_create(pPacket, inet_addr_src, 68, inet_addr_dst, 67, &dhcp, sizeof(DHCP)- sizeof(dhcp_option_t) + options.size);
+	UDP_create(pPacket, inet_addr_src, 68, inet_addr_dst, 67, &dhcp, sizeof(DHCP));
 }
 
 void option_list_init(option_list_t *pObj, void *pBuffer, size_t size)
@@ -122,4 +135,4 @@ size_t data_entry_create(void *pDst, uint8_t type, void const *pData, size_t siz
 	pDst8 += size;
 	
 	return (size_t)(pDst8 - (uint8_t*)pDst);
-}
\ No newline at end of file
+}
diff --git a/src/common/network/dhcp.h b/src/common/network/dhcp.h
index 32b306b..c75f54c 100644
--- a/src/common/network/dhcp.h
+++ b/src/common/network/dhcp.h
@@ -53,10 +53,21 @@ typedef struct _soption_list_t
 
 #define DHCP_FLAGS_BROADCAST	0x8000
 
+#define	DHCP_OPT_SUBNETMASK		1
+#define	DHCP_OPT_TIME_OFFSET	2
+#define	DHCP_OPT_ROUTER			3
+#define	DHCP_OPT_TIMESERVER		4
+
+#define	DHCP_OPT_NAMESERVER		5
+#define	DHCP_OPT_DOMAIN_NS		6
 #define	DHCP_OPT_HOSTNAME		12
+#define	DHCP_OPT_DOMAIN_NAME	15
 #define	DHCP_OPT_REQIP			50
 #define	DHCP_OPT_MSGTYPE		53
 #define	DHCP_OPT_SERVERID		54
+#define	DHCP_OPT_PARAM_REQ_LIST	55
+
+#define	DHCP_OPT_VENDORID		60
 #define	DHCP_OPT_CLIENTID		61
 #define	DHCP_OPT_END			255
 
diff --git a/src/common/network/emac.c b/src/common/network/emac.c
index 7049248..26f6f85 100644
--- a/src/common/network/emac.c
+++ b/src/common/network/emac.c
@@ -8,6 +8,30 @@
 
 #include <libsys/libsys.h>
 
+void EMAC_MACADDR_set(uint8_t const *macAddr)
+{
+	volatile uint32_t *pEmac_maddr = (uint32_t*)SYS_EMAC_MADDR;
+	uint32_t dword = 0;
+	
+	int idx = 0;
+	while(idx < 4)
+	{
+		dword <<= 8;
+		dword |= (uint32_t)macAddr[idx++];
+	}
+	*(pEmac_maddr+0) = dword;
+	
+	dword = 0;
+	while(idx < 6)
+	{
+		dword <<= 8;
+		dword |= (uint32_t)macAddr[idx++];
+	}
+	dword <<= 16;
+	*(pEmac_maddr+1) = dword;
+
+}
+
 void EMAC_TX_commit(void)
 {
 
diff --git a/src/common/network/emac.h b/src/common/network/emac.h
index caaba15..b79fa64 100644
--- a/src/common/network/emac.h
+++ b/src/common/network/emac.h
@@ -4,6 +4,7 @@
 #include <sys/types.h>
 #include <libsys/libsys.h>
 
+void EMAC_MACADDR_set(uint8_t const *macAddr);
 void EMAC_TX_commit(void);
 void EMAC_TX_alloc(uint32_t size);
 uint32_t EMAC_TX_is_avail(void);
diff --git a/src/common/network/ipv4.c b/src/common/network/ipv4.c
index 623e41e..141f351 100644
--- a/src/common/network/ipv4.c
+++ b/src/common/network/ipv4.c
@@ -27,9 +27,9 @@ uint8_t *IPV4_create(packet_t *pPacket, uint16_t proto, uint16_t len, uint8_t *i
 	pIPv4_hdr->ver_ihl = 0x45;
 	pIPv4_hdr->tos = 0x00;
 	pIPv4_hdr->len = sizeof(IPV4) + len;
-	pIPv4_hdr->id = 0x1234;
+	pIPv4_hdr->id = 0x0000;
 	pIPv4_hdr->flag_foff = 0; //IPV4_FLAG_DF;
-	pIPv4_hdr->ttl = 0x10;
+	pIPv4_hdr->ttl = 0x40;
 	pIPv4_hdr->proto = proto;
 
 	pIPv4_hdr->hdr_chksum = 0x0000;
diff --git a/src/common/network/udp.c b/src/common/network/udp.c
index c0f6df3..78cb79c 100644
--- a/src/common/network/udp.c
+++ b/src/common/network/udp.c
@@ -33,7 +33,10 @@ uint8_t *UDP_create(packet_t *pPacket, uint8_t *inet_addr_src, uint16_t port_src
 	pseudo_hdr.len = len + sizeof(UDP);
 
 	// Calculate checksums
-	pUDP->chksum = ~IPv4ChkSum((uint16_t*)&pseudo_hdr, pUDP->chksum, sizeof(UDPPP));
+	uint16_t chksum = 0;
+	chksum = IPv4ChkSum((uint16_t*)&pseudo_hdr, chksum, sizeof(UDPPP));
+	chksum = IPv4ChkSum((uint16_t*)pUDP, chksum, sizeof(UDP));
+	pUDP->chksum = ~IPv4ChkSum((uint16_t*)pUDP_payload, chksum, len);
 
 	// Commit header
 	pData = (uint8_t*)Eth_pkt_append(pPacket, sizeof(UDP));
@@ -57,4 +60,4 @@ void UDP_append(packet_t *pPacket, void const *pData, uint16_t len)
 		memcpy(pPacket->pData, pData, len);
 		Eth_pkt_append(pPacket, len);
 	}
-}
\ No newline at end of file
+}