diff -Naur dns.h dns.h
--- dns.h	2000-03-18 16:18:42.000000000 +0100
+++ dns.h	2011-06-02 19:18:55.000000000 +0200
@@ -4,6 +4,7 @@
 #include "stralloc.h"
 #include "iopause.h"
 #include "taia.h"
+#include "uint16.h"
 
 #define DNS_C_IN "\0\1"
 #define DNS_C_ANY "\0\377"
@@ -35,6 +36,7 @@
   struct taia deadline;
   unsigned int pos;
   char *servers;
+  uint16 port;
   char localip[4];
   char qtype[2];
 } ;
diff -Naur dns_transmit.c dns_transmit.c
--- dns_transmit.c	2000-03-18 16:18:42.000000000 +0100
+++ dns_transmit.c	2011-06-02 19:19:47.000000000 +0200
@@ -5,6 +5,7 @@
 #include "readwrite.h"
 #include "uint16.h"
 #include "dns.h"
+#include "env.h"
 
 static int serverwantstcp(char *buf,unsigned int len)
 {
@@ -109,7 +110,7 @@
         if (!d->s1) { dns_transmit_free(d); return -1; }
 	if (randombind(d) == -1) { dns_transmit_free(d); return -1; }
 
-        if (socket_connect4(d->s1 - 1,ip,53) == 0)
+        if (socket_connect4(d->s1 - 1,ip,d->port) == 0)
           if (send(d->s1 - 1,d->query + 2,d->querylen - 2,0) == d->querylen - 2) {
             struct taia now;
             taia_now(&now);
@@ -163,7 +164,7 @@
       taia_now(&now);
       taia_uint(&d->deadline,10);
       taia_add(&d->deadline,&d->deadline,&now);
-      if (socket_connect4(d->s1 - 1,ip,53) == 0) {
+      if (socket_connect4(d->s1 - 1,ip,d->port) == 0) {
         d->tcpstate = 2;
         return 0;
       }
@@ -211,6 +212,8 @@
 
   byte_copy(d->qtype,2,qtype);
   d->servers = servers;
+  d->port = 53;
+  if (env_get("DNSCACHEPORT")) scan_ulong(env_get("DNSCACHEPORT"),&d->port);
   byte_copy(d->localip,4,localip);
 
   d->udploop = flagrecursive ? 1 : 0;