--- nProbe/nprobe.c	2006-06-09 05:30:39.000000000 -0500
+++ nProbe.new/nprobe.c	2007-05-07 17:35:37.677224000 -0500
@@ -241,8 +241,10 @@
   u_short eth_type, off=0, numPkts = 1;
   u_int8_t flags = 0, proto = 0;
   struct ip ip;
+  #ifndef IPV4_ONLY
   struct ip6_hdr ipv6;
   struct ip6_ext ipv6ext;
+  #endif
   struct tcphdr tp;
   struct udphdr up;
   struct icmp icmpPkt;
@@ -362,7 +364,9 @@
 	isFragment = (ntohs(ip.ip_off) & 0x3fff) ? 1 : 0;
 
 	off = ntohs(ip.ip_off);
-      } else if(eth_type == ETHERTYPE_IPV6) {
+      } 
+      #ifndef IPV4_ONLY
+      else if(eth_type == ETHERTYPE_IPV6) {
 	memcpy(&ipv6, p+ehshift, sizeof(struct ip6_hdr));
 	if(((ipv6.ip6_vfc >> 4) & 0x0f) != 6) return; /* IP v6 only */
 	estimatedLen = sizeof(struct ip6_hdr)+ehshift+htons(ipv6.ip6_plen);
@@ -392,7 +396,9 @@
 	  hlen += (ipv6ext.ip6e_len+1)*8;
 	  proto = ipv6ext.ip6e_nxt;
 	}
-      } else
+      } 
+     #endif //IPV4_ONLY
+      else
 	return; /* Anything else that's not IPv4/v6 */
 
       plen = length-ehshift;
