diff --git a/src/common/network/dhcp.c b/src/common/network/dhcp.c
index addfda1..88c3aa9 100644
--- a/src/common/network/dhcp.c
+++ b/src/common/network/dhcp.c
@@ -65,10 +65,14 @@ void DHCP_request_send(packet_t *pPacket, uint32_t dhcp_msg_type, uint8_t *mac_a
 		size = sizeof(dhcp_opt_hdr_t);
 		pOpt_hdr = (dhcp_opt_hdr_t*)&pDHCP->options[option_size];
 		pOpt_hdr->code = DHCP_OPT_CLIENTID;
-		pOpt_hdr->len = 6;
+		pOpt_hdr->len = 7;
 		option_size += size;
 
-		size = pOpt_hdr->len;
+		size = 1;
+		pDHCP->options[option_size] = HWTYPE_ETHERNET;
+		option_size += size;
+		
+		size = 6;
 		memcpy(&pDHCP->options[option_size], mac_addr_src, size);
 		option_size += size;
 #endif
@@ -116,10 +120,14 @@ void DHCP_request_send(packet_t *pPacket, uint32_t dhcp_msg_type, uint8_t *mac_a
 		size = sizeof(dhcp_opt_hdr_t);
 		pOpt_hdr = (dhcp_opt_hdr_t*)&pDHCP->options[option_size];
 		pOpt_hdr->code = DHCP_OPT_CLIENTID;
-		pOpt_hdr->len = 6;
+		pOpt_hdr->len = 7;
 		option_size += size;
 
-		size = pOpt_hdr->len;
+		size = 1;
+		pDHCP->options[option_size] = HWTYPE_ETHERNET;
+		option_size += size;
+		
+		size = 6;
 		memcpy(&pDHCP->options[option_size], mac_addr_src, size);
 		option_size += size;
 #endif
diff --git a/src/common/network/dhcp.h b/src/common/network/dhcp.h
index 105c827..8adf925 100644
--- a/src/common/network/dhcp.h
+++ b/src/common/network/dhcp.h
@@ -56,6 +56,27 @@ typedef struct _sdhcp_opt_hdr_t
 #define	DHCP_MSG_DHCPNAK		6
 #define	DHCP_MSG_DHCPRELEASE	7
 
+// Hardware types RFC 1340
+#define HWTYPE_ETHERNET			1
+/*
+		1    Ethernet (10Mb)                                    [JBP]
+        2    Experimental Ethernet (3Mb)                        [JBP]
+        3    Amateur Radio AX.25                                [PXK]
+        4    Proteon ProNET Token Ring                          [JBP]
+        5    Chaos                                              [GXP]
+        6    IEEE 802 Networks                                  [JBP]
+        7    ARCNET                                             [JBP]
+        8    Hyperchannel                                       [JBP]
+        9    Lanstar                                             [TU]
+       10    Autonet Short Address                             [MXB1]
+       11    LocalTalk                                         [JKR1]
+       12    LocalNet (IBM PCNet or SYTEK LocalNET)             [JXM]
+       13    Ultra link                                        [RXD2]
+       14    SMDS                                              [GXC1]
+       15    Frame Relay                                        [AGM]
+       16    Asynchronous Transmission Mode (ATM)              [JXB2]
+*/
+
 // -------------------------------------------------------------------------
 void DHCP_request_send(packet_t *pPacket, uint32_t dhcp_msg_type, uint8_t *mac_addr_src, uint8_t *inet_addr_src, uint8_t *inet_addr_dst, DHCP *pLast);