diff --git a/TODO b/TODO
index fa97bac..fd87a76 100644
--- a/TODO
+++ b/TODO
@@ -2,3 +2,4 @@
  * Have one more look at IPv6 extension headers
  * Add support for type-1, type-2 routing headers
  * Add support for short form of IPv6 prefix in RA prefix option
+ * MAC validation is yet to be added
diff --git a/conf b/conf
index 680ac15..682355a 100644
--- a/conf
+++ b/conf
@@ -20,35 +20,12 @@ IPV6_DST_ADDR=E23::9AD
 IPV6_EXT_HDRS=0
 
 ICMP6
-ICMP6_TYPE=134
+ICMP6_TYPE=128
 ICMP6_CODE=0
 ICMP6_CHECKSUM=-1
 
-NDISC_RA
-NDISC_RA_CUR_HOP_LIMIT=124
-NDISC_RA_M_FLAG=1
-NDISC_RA_O_FLAG=1
-NDISC_RA_ROUTER_LIFETIME=1223
-NDISC_RA_REACHABLE_TIME=2342
-NDISC_RA_RETRANS_TIMER=45543
-NDISC_RA_OPTION_NUM=3
-
-NDISC_RA_OPTION=NDISC_RA_PREFIX_INFO
-NDISC_RA_OP_TYPE=3
-NDISC_RA_OP_LEN=4
-NDISC_RA_PREFIX_LEN=64
-NDISC_RA_L_FLAG=1
-NDISC_RA_A_FLAG=0
-NDISC_RA_PREFIX_VALID_LIFETIME=12345
-NDISC_RA_PREFIX_PREFERRED_LIFETIME=54321
-NDISC_RA_PREFIX=2001:23
-
-NDISC_RA_OPTION=NDISC_RA_SRC_LINK_ADDR
-NDISC_RA_OP_TYPE=1
-NDISC_RA_OP_LEN=1
-NDISC_RA_OP_SRC_LINK_ADDR=00:01:02:03:04:05
-
-NDISC_RA_OPTION=NDISC_RA_MTU
-NDISC_RA_OP_TYPE=5
-NDISC_RA_OP_LEN=1
-NDISC_RA_MTU=245
+ECHO6
+ECHO6_IDENTIFIER=1234
+ECHO6_SEQ=3
+#ECHO6_DATA=NO_DATA
+ECHO6_DATA=0xff00ff
diff --git a/conf.help b/conf.help
index 2b17bcc..ce0b9ad 100644
--- a/conf.help
+++ b/conf.help
@@ -1,3 +1,8 @@
+	This is help file for the pgen configuration file. It gives a minimal
+information about all possible options. pgen expects the user to give options
+in the same order that appears in a packet. Also some sample conf files have
+been given in sample_confs directory.
+
 						***** Common *****
 1. BUFF_SIZE
 	Size of the packet buffer. Any decimal number in the range of an 32-bit
@@ -283,6 +288,7 @@ are,
 	Type of RA option. pgen supports following types,
 		NDISC_RA_PREFIX_INFO		3
 		NDISC_RA_SRC_LINK_ADDR		1
+		NDISC_RA_TAR_LINK_ADDR		1
 		NDISC_RA_MTU				5
 
 11. NDISC_RA_OP_LEN
@@ -311,9 +317,96 @@ user has to give full prefix value.
 --- For Source Link Layer Address option ---
 18. NDISC_RA_OP_SRC_LINK_ADDR
 	The Source Link Layer Address. As of now the MAC address of the underlying
-hardware.
+hardware. For Target Link Layer Address option, use NDISC_RA_TYPE value 2.
 
 --- For MTU option ---
 19. NDISC_RA_MTU
 	The MTU value.
 -------------------------------------------------------------------------------
+
+Router Solicitation------------------------------------------------------------
+1. NDISC_RS
+	Starting of Router Solicitation message
+
+2. NDISC_RS_OPTION
+	The Router Solicitaion option. pgen supports followint RS options
+		NDISC_RS_SRC_LINK_ADDR
+
+3. NDISC_RS_OP_TYPE
+	Option type for the RS option. For Target Source Link Layer address option
+use NDISC_RS_OP_TYPE as 2
+
+4. NDISC_RS_OP_LEN
+	Option length in 8-bit octet unit.
+
+5. NDISC_RS_SRC_LINK_ADDR
+	The Link Layer Address. As of now the Hardware mac address Source/Target
+-------------------------------------------------------------------------------
+
+Neighbor Advertisement---------------------------------------------------------
+1. NDISC_NA
+	NA data starts here
+
+2. NDISC_NA_R
+	NA R flag. 1 for set and 0 for reset
+
+3. NDISC_NA_S
+	NA S flag. 1 for set and 0 for reset
+
+4. NDISC_NA_O
+	NA O flag. 1 for set and 0 for reset
+
+5. NDISC_NA_TARGET_ADDR
+	The target address from which this advertisement is being sent
+
+6. NDISC_NA_OPTION
+	The NA option. pgen supports
+		NDISC_NA_SRC_LINK_ADDR
+
+7. NDISC_NA_OP_TYPE
+	Type of NA option. For Target Link Layer Address, type will be 2
+
+8. NDISC_NA_OP_LEN
+	Length of NA option in 8-octets unit
+
+9. NDISC_NA_OP_TAR_LINK_ADDR
+	The Target Link Layer Address. The Hardware MAC address.
+-------------------------------------------------------------------------------
+
+Neighbor Solicitation----------------------------------------------------------
+1. NDISC_NS
+	Neighbor Solicitaion starts here
+
+2. NDISC_NS_TARGET_ADDR
+	Target Address of NS
+
+3. NDISC_NS_OPTION
+	Neighbor Soliciation option. The only supported option is
+		NDISC_NS_SRC_LINK_ADDR
+
+3. NDISC_NS_OP_TYPE
+	Type of NS option. 1 for Source Link Layer Address option and 2 for Target
+Link Layer Address option.
+
+4. NDISC_NS_OP_LEN
+	Length of NS option in 8-octets unit
+
+5. NDISC_NS_OP_SRC_LINK_ADDR
+	Source Link Layer Address. The hardware MAC address of the sender.
+-------------------------------------------------------------------------------
+
+ICMPv6 Echo--------------------------------------------------------------------
+1. ECHO6
+	The ICMPv6 Echo packet starts here
+
+2. ECHO6_IDENTIFIER
+	Identifier of the Echo6 packet
+
+3. ECHO6_SEQ
+	Sequence of Echo6 packet
+
+4. ECHO6_DATA
+	Data for Echo6 packet.
+			NO_DATA		For no data
+	Or the user has to give the data he wants in hex.
+-------------------------------------------------------------------------------
diff --git a/icmp6.c b/icmp6.c
index 5b1baf4..b187834 100644
--- a/icmp6.c
+++ b/icmp6.c
@@ -562,6 +562,7 @@ char* pgen_ndisc_rs_writer(FILE *fp, char *cp_cur) {
 
 		/* Source Link Layer address and the only known option */
 		else if (!strcmp(value, "NDISC_RS_SRC_LINK_ADDR")) {
+			op = (char *)&(pkt->option);
 			if (pgen_parse_option(fp, option, value))
 				goto err;
 			if (!strcmp(option, "NDISC_RS_OP_TYPE")) {
@@ -757,6 +758,7 @@ char* pgen_ndisc_na_writer(FILE *fp, char *cp_cur) {
 
 			/* This is only known option as of now. [RFC-4861] */
 			else if (!strcmp(value, "NDISC_NA_SRC_LINK_ADDR")) {
+				op_ptr = (char *)&(pkt->option);
 
 				if (pgen_parse_option(fp, option, value))
 					goto err;
@@ -866,9 +868,7 @@ char* pgen_icmp6_writer(FILE *fp, char *cp_cur) {
 
 	if (!strcmp(option, "NO_ICMP6_BODY"));
 		/* we are fine here. Do nothing */
-	else if (!strcmp(option, "ECHO_REQ"))
-		cp_cur = pgen_echo6_writer(fp, cp_cur);
-	else if (!strcmp(option, "ECHO_REP"))
+	else if (!strcmp(option, "ECHO6"))
 		cp_cur = pgen_echo6_writer(fp, cp_cur);
 	else if (!strcmp(option, "NDISC_NS"))
 		cp_cur = pgen_ndisc_ns_writer(fp, cp_cur);
diff --git a/sample_confs/conf_icmp6_NA.txt b/sample_confs/conf_icmp6_NA.txt
new file mode 100644
index 0000000..9c629d7
--- /dev/null
+++ b/sample_confs/conf_icmp6_NA.txt
@@ -0,0 +1,35 @@
+BUFF_SIZE=1024
+
+IF_NAME=lo
+PK_DST_MAC=00:01:9B:04:03:3C
+
+ETHER_HEADER
+DST_MAC=ff:ff:ff:ff:ff:ff
+SRC_MAC=5C:D9:98:C1:8E:FE
+ETHR_TYPE=34525
+
+IPV6
+IPV6_VERSION=6
+IPV6_TRAFFIC_CLASS=255
+IPV6_FLOW_LABEL=1234
+IPV6_PAYLOAD_LENGTH=64
+IPV6_NEXT_HEADER=58
+IPV6_HOP_LIMIT=128
+IPV6_SRC_ADDR=fe80::213
+IPV6_DST_ADDR=E23::9AD
+IPV6_EXT_HDRS=0
+
+ICMP6
+ICMP6_TYPE=136
+ICMP6_CODE=0
+ICMP6_CHECKSUM=-1
+
+NDISC_NA
+NDISC_NA_R=1
+NDISC_NA_S=0
+NDISC_NA_O=1
+NDISC_NA_TARGET_ADDR=fe89::34
+NDISC_NA_OPTION=NDISC_NA_SRC_LINK_ADDR
+NDISC_NA_OP_TYPE=2
+NDISC_NA_OP_LEN=1
+NDISC_NA_OP_TAR_LINK_ADDR=12:AB:34:CD:56:EF
diff --git a/sample_confs/conf_icmp6_NS.txt b/sample_confs/conf_icmp6_NS.txt
new file mode 100644
index 0000000..b77e41a
--- /dev/null
+++ b/sample_confs/conf_icmp6_NS.txt
@@ -0,0 +1,32 @@
+BUFF_SIZE=1024
+
+IF_NAME=lo
+PK_DST_MAC=00:01:9B:04:03:3C
+
+ETHER_HEADER
+DST_MAC=ff:ff:ff:ff:ff:ff
+SRC_MAC=5C:D9:98:C1:8E:FE
+ETHR_TYPE=34525
+
+IPV6
+IPV6_VERSION=6
+IPV6_TRAFFIC_CLASS=255
+IPV6_FLOW_LABEL=1234
+IPV6_PAYLOAD_LENGTH=64
+IPV6_NEXT_HEADER=58
+IPV6_HOP_LIMIT=128
+IPV6_SRC_ADDR=fe80::213
+IPV6_DST_ADDR=E23::9AD
+IPV6_EXT_HDRS=0
+
+ICMP6
+ICMP6_TYPE=135
+ICMP6_CODE=0
+ICMP6_CHECKSUM=-1
+
+NDISC_NS
+NDISC_NS_TARGET_ADDR=2001::24
+NDISC_NS_OPTION=NDISC_NS_SRC_LINK_ADDR
+NDISC_NS_OP_TYPE=2
+NDISC_NS_OP_LEN=1
+NDISC_NS_OP_SRC_LINK_ADDR=90:87:87:12:34:44
diff --git a/sample_confs/conf_icmp6_RS.txt b/sample_confs/conf_icmp6_RS.txt
new file mode 100644
index 0000000..7198b00
--- /dev/null
+++ b/sample_confs/conf_icmp6_RS.txt
@@ -0,0 +1,31 @@
+BUFF_SIZE=1024
+
+IF_NAME=lo
+PK_DST_MAC=00:01:9B:04:03:3C
+
+ETHER_HEADER
+DST_MAC=ff:ff:ff:ff:ff:ff
+SRC_MAC=5C:D9:98:C1:8E:FE
+ETHR_TYPE=34525
+
+IPV6
+IPV6_VERSION=6
+IPV6_TRAFFIC_CLASS=255
+IPV6_FLOW_LABEL=1234
+IPV6_PAYLOAD_LENGTH=64
+IPV6_NEXT_HEADER=58
+IPV6_HOP_LIMIT=128
+IPV6_SRC_ADDR=fe80::213
+IPV6_DST_ADDR=E23::9AD
+IPV6_EXT_HDRS=0
+
+ICMP6
+ICMP6_TYPE=133
+ICMP6_CODE=0
+ICMP6_CHECKSUM=-1
+
+NDISC_RS
+NDISC_RS_OPTION=NDISC_RS_SRC_LINK_ADDR
+NDISC_RS_OP_TYPE=2
+NDISC_RS_OP_LEN=1
+NDISC_RS_OP_SRC_LINK_ADDR=12:23:34:45:56:ab
diff --git a/sample_confs/conf_icmp6_echo6.txt b/sample_confs/conf_icmp6_echo6.txt
new file mode 100644
index 0000000..682355a
--- /dev/null
+++ b/sample_confs/conf_icmp6_echo6.txt
@@ -0,0 +1,31 @@
+BUFF_SIZE=1024
+
+IF_NAME=lo
+PK_DST_MAC=00:01:9B:04:03:3C
+
+ETHER_HEADER
+DST_MAC=ff:ff:ff:ff:ff:ff
+SRC_MAC=5C:D9:98:C1:8E:FE
+ETHR_TYPE=34525
+
+IPV6
+IPV6_VERSION=6
+IPV6_TRAFFIC_CLASS=255
+IPV6_FLOW_LABEL=1234
+IPV6_PAYLOAD_LENGTH=64
+IPV6_NEXT_HEADER=58
+IPV6_HOP_LIMIT=128
+IPV6_SRC_ADDR=fe80::213
+IPV6_DST_ADDR=E23::9AD
+IPV6_EXT_HDRS=0
+
+ICMP6
+ICMP6_TYPE=128
+ICMP6_CODE=0
+ICMP6_CHECKSUM=-1
+
+ECHO6
+ECHO6_IDENTIFIER=1234
+ECHO6_SEQ=3
+#ECHO6_DATA=NO_DATA
+ECHO6_DATA=0xff00ff