Index: scan_engine.cc
===================================================================
--- scan_engine.cc      (revision 31520)
+++ scan_engine.cc      (working copy)
@@ -311,6 +311,7 @@
     return (pingseq == 0 && tryno == this->tryno) || (pingseq > 0 && pingseq == this->pingseq);
   }

+  u16 icmp_ident;
   u8 tryno; /* Try (retransmission) number of this probe */
   u8 pingseq; /* 0 if this is not a scanping. Otherwise a posative ping seq#. */
   /* If true, probe is considered no longer active due to timeout, but it
@@ -3624,6 +3625,7 @@
       hss->probeSent(packetlen);
       send_ip_packet(USI->rawsd, ethptr, hss->target->TargetSockAddr(), packet, packetlen);
       free(packet);
+      probe->icmp_ident = icmp_ident;
     }
   } else if (pspec->type == PS_ICMPV6) {
     struct sockaddr_storage source;
@@ -5053,6 +5055,12 @@
               probe->ipid() == hdr.ipid)
             continue; /* We saw the packet we ourselves sent */

+          if (ntohs(ping->seq) != probe->tryno)
+            continue;
+
+          if (ntohs(ping->id) != probe->icmp_ident)
+            continue;
+
           goodone = true;
           newstate = HOST_UP;