diff --git a/scripts/ipv6-node-info.nse b/scripts/ipv6-node-info.nse
index 2104a509d..56f280aa0 100644
--- a/scripts/ipv6-node-info.nse
+++ b/scripts/ipv6-node-info.nse
@@ -244,16 +244,14 @@ local STRINGIFY = {
 }
 
 local function handle_received_packet(buf)
-  local p, qtype, flags, data
   local text
 
-  p = packet.Packet:new(buf)
+  local p = packet.Packet:new(buf)
   if p.icmpv6_type ~= ICMPv6_NODEINFORESP then
     return
   end
-  qtype = packet.u16(p.buf, p.icmpv6_offset + 4)
-  flags = packet.u16(p.buf, p.icmpv6_offset + 6)
-  data = string.sub(p.buf, p.icmpv6_offset + 16 + 1)
+  local qtype, flags, pos = string.unpack(">I2I2", p.buf, p.icmpv6_offset + 4)
+  local data = string.sub(p.buf, pos + 8)
 
   if not STRINGIFY[qtype] then
     -- This is a not a qtype we sent or know about.
diff --git a/scripts/ipv6-ra-flood.nse b/scripts/ipv6-ra-flood.nse
index 9737b46ac..0ecc4e027 100644
--- a/scripts/ipv6-ra-flood.nse
+++ b/scripts/ipv6-ra-flood.nse
@@ -106,14 +106,18 @@ local function build_router_advert(mac_src,prefix,prefix_len,valid_time,preferre
   0x00,0x00,0x00,0x00, --reachable time
   0x00,0x00,0x00,0x00) --retrans timer
 
-  local mtu_option_msg = "\0\0" .. -- reserved
-  packet.numtostr32(mtu) -- MTU
+  local mtu_option_msg = string.pack(">I2 I4",
+    0, -- reserved
+    mtu -- MTU
+    )
 
-  local prefix_option_msg = string.char(prefix_len, 0xc0) .. --flags: Onlink, Auto
-  packet.set_u32("....", 0, valid_time) .. -- valid lifetime
-  packet.set_u32("....", 0, preferred_time) .. -- preferred lifetime
-  "\0\0\0\0" .. --unknown
-  prefix
+  local prefix_option_msg = string.pack(">BB I4 I4 I4",
+    prefix_len,
+    0xc0, --flags: Onlink, Auto
+    valid_time, -- valid lifetime
+    preferred_time, -- preferred lifetime
+    0 -- unknown
+    ) .. prefix
 
   local icmpv6_mtu_option = packet.Packet:set_icmpv6_option(packet.ND_OPT_MTU, mtu_option_msg)
   local icmpv6_prefix_option = packet.Packet:set_icmpv6_option(packet.ND_OPT_PREFIX_INFORMATION, prefix_option_msg)
diff --git a/scripts/targets-ipv6-multicast-slaac.nse b/scripts/targets-ipv6-multicast-slaac.nse
index 09457623c..d924e6ced 100644
--- a/scripts/targets-ipv6-multicast-slaac.nse
+++ b/scripts/targets-ipv6-multicast-slaac.nse
@@ -82,11 +82,13 @@ local function build_router_advert(mac_src,prefix,prefix_len,valid_time,preferre
   0x00,0x00, --router lifetime
   0x00,0x00,0x00,0x00, --reachable time
   0x00,0x00,0x00,0x00) --retrans timer
-  local prefix_option_msg = string.char(prefix_len, 0xc0) .. --flags: Onlink, Auto
-    packet.set_u32("....",0,valid_time) ..
-    packet.set_u32("....",0,preferred_time) ..
-    "\0\0\0\0" .. --unknown
-    prefix
+  local prefix_option_msg = string.pack(">BB I4 I4 I4",
+    prefix_len,
+    0xc0, --flags: Onlink, Auto
+    valid_time, -- valid lifetime
+    preferred_time, -- preferred lifetime
+    0 -- unknown
+    ) .. prefix
   local icmpv6_prefix_option = packet.Packet:set_icmpv6_option(packet.ND_OPT_PREFIX_INFORMATION,prefix_option_msg)
   local icmpv6_src_link_option = packet.Packet:set_icmpv6_option(packet.ND_OPT_SOURCE_LINKADDR,mac_src)
   local icmpv6_payload = ra_msg .. icmpv6_prefix_option .. icmpv6_src_link_option