diff --git a/llarp/handlers/tun.cpp b/llarp/handlers/tun.cpp
index ae6d57e6f..7d296d348 100644
--- a/llarp/handlers/tun.cpp
+++ b/llarp/handlers/tun.cpp
@@ -209,14 +209,15 @@ namespace llarp
       uint32_t usIP   = m_OurIP;
       auto buf        = llarp::Buffer(msg->payload);
       net::IPv4Packet pkt;
-      memcpy(pkt.buf, buf.base, std::min(buf.sz, sizeof(pkt.buf)));
+      pkt.sz = std::min(buf.sz, sizeof(pkt.buf));
+      memcpy(pkt.buf, buf.base, pkt.sz);
       pkt.src(themIP);
       pkt.dst(usIP);
       pkt.UpdateChecksum();
       llarp::LogInfo(Name(), " handle data message ", msg->payload.size(),
                      " bytes from ", inet_ntoa({htonl(themIP)}));
-
       llarp_ev_tun_async_write(&tunif, pkt.buf, pkt.sz);
+
       /*
       if(!m_NetworkToUserPktQueue.EmplaceIf(
              [buf, themIP, usIP](net::IPv4Packet &pkt) -> bool {
diff --git a/llarp/ip.cpp b/llarp/ip.cpp
index b83e7b3a5..2ec9023f1 100644
--- a/llarp/ip.cpp
+++ b/llarp/ip.cpp
@@ -3,6 +3,8 @@
 #include <llarp/ip.hpp>
 #include "llarp/buffer.hpp"
 #include "mem.hpp"
+#include <netinet/in.h>
+#include <map>
 
 namespace llarp
 {
@@ -26,29 +28,44 @@ namespace llarp
       return llarp::InitBuffer(buf, sz);
     }
 
-    void
-    IPv4Packet::UpdateChecksum()
-    {
-      auto hdr   = Header();
-      hdr->check = 0;
+    /// bytes offset to checksum relative to end of ip header for each protocol
+    static std::map< byte_t, uint16_t > protoChecksumOffsets = {
+        {IPPROTO_TCP, 16}, {IPPROTO_ICMP, 2}, {IPPROTO_UDP, 6}};
 
-      size_t count = hdr->ihl;
+    static uint16_t
+    ipchksum(const byte_t *buf, size_t sz)
+    {
       uint32_t sum = 0;
-      byte_t *addr = buf;
-
-      while(count > 1)
+      while(sz > 1)
       {
-        sum += *(uint16_t *)addr;
-        count -= sizeof(uint16_t);
-        addr += sizeof(uint16_t);
+        sum += *(const uint16_t *)buf;
+        sz -= sizeof(uint16_t);
+        buf += sizeof(uint16_t);
       }
-      if(count > 0)
-        sum += *(byte_t *)addr;
+      if(sz > 0)
+        sum += *(const byte_t *)buf;
 
       while(sum >> 16)
         sum = (sum & 0xffff) + (sum >> 16);
 
-      hdr->check = ~sum;
+      return ~sum;
+    }
+
+    void
+    IPv4Packet::UpdateChecksum()
+    {
+      auto hdr   = Header();
+      hdr->check = 0;
+      auto len   = hdr->ihl * 4;
+      hdr->check = ipchksum(buf, len);
+
+      auto itr = protoChecksumOffsets.find(hdr->protocol);
+      if(itr != protoChecksumOffsets.end())
+      {
+        uint16_t *check = (uint16_t *)(buf + len + itr->second);
+        *check          = 0;
+        *check          = ipchksum(buf, sz);
+      }
     }
 
   }  // namespace net
diff --git a/llarp/service/endpoint.cpp b/llarp/service/endpoint.cpp
index 434fcb25a..88471e93f 100644
--- a/llarp/service/endpoint.cpp
+++ b/llarp/service/endpoint.cpp
@@ -820,7 +820,7 @@ namespace llarp
     Endpoint::OutboundContext::OnIntroSetUpdate(const Address& addr,
                                                 const IntroSet* i)
     {
-      if(i && addr == i->A.Addr() && currentIntroSet.OtherIsNewer(*i))
+      if(i)
       {
         currentIntroSet = *i;
         ShiftIntroduction();
@@ -837,8 +837,9 @@ namespace llarp
         auto itr = m_AddressToService.find(remote);
         if(itr != m_AddressToService.end())
         {
-          ProtocolFrame f;
-          path::Path* p = nullptr;
+          routing::PathTransferMessage transfer;
+          ProtocolFrame& f = transfer.T;
+          path::Path* p    = nullptr;
           std::set< ConvoTag > tags;
           if(!GetConvoTagsForService(itr->second, tags))
           {
@@ -869,18 +870,20 @@ namespace llarp
             return false;
           }
           ProtocolMessage m(f.T);
-          m.PutBuffer(data);
           m.proto      = t;
           m.introReply = p->intro;
           m.sender     = m_Identity.pub;
+          m.PutBuffer(data);
           f.N.Randomize();
+          f.S = GetSeqNoForConvo(f.T);
           f.C.Zero();
+          transfer.Y.Randomize();
+          transfer.P = intro.pathID;
           if(!f.EncryptAndSign(&Router()->crypto, m, K, m_Identity))
           {
             llarp::LogError("failed to encrypt and sign");
             return false;
           }
-          routing::PathTransferMessage transfer(f, intro.pathID);
           return p->SendRoutingMessage(&transfer, Router());
         }
       }
diff --git a/llarp/service/protocol.cpp b/llarp/service/protocol.cpp
index a4fb75434..dcf5fe1c4 100644
--- a/llarp/service/protocol.cpp
+++ b/llarp/service/protocol.cpp
@@ -248,7 +248,7 @@ namespace llarp
         if(!self->frame->Verify(crypto, self->msg->sender))
         {
           llarp::LogError("intro frame has invalid signature Z=",
-                          self->frame->Z, " from ", self->msg->sender);
+                          self->frame->Z, " from ", self->msg->sender.Addr());
           delete self->msg;
           delete self;
           return;