diff --git a/CHANGELOG b/CHANGELOG
index c97554f5..5fa50a18 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -23,6 +23,9 @@ HISTORY
 
   ++ New features:
   
+  2007-03-08 Simon Goldschmidt
+  * snmp_msg.h, msg_in.c: SNMP UDP ports can be configured at compile time.
+
   2007-03-06 Frédéric Bernon
   * api.h, api_lib.c, sockets.h, sockets.c, tcpip.c, sys.h, sys.c, err.h: 
     Implement SO_RCVTIMEO on UDP sockets/netconn.
diff --git a/src/core/snmp/msg_in.c b/src/core/snmp/msg_in.c
index d0718501..898c5604 100644
--- a/src/core/snmp/msg_in.c
+++ b/src/core/snmp/msg_in.c
@@ -807,7 +807,7 @@ snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
   udphdr = p->payload;
 
   /* check if datagram is really directed at us (including broadcast requests) */
-  if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == 161))
+  if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == SNMP_IN_PORT))
   {
     struct snmp_msg_pstat *msg_ps;
     u8_t req_idx;
diff --git a/src/include/lwip/snmp_msg.h b/src/include/lwip/snmp_msg.h
index 66faedd4..2e126ebe 100644
--- a/src/include/lwip/snmp_msg.h
+++ b/src/include/lwip/snmp_msg.h
@@ -44,8 +44,16 @@
 #include "private_mib.h"
 #endif
 
+/* The listen port of the SNMP agent. Clients have to make their requests to
+   this port. Most standard clients won't work if you change this! */
+#ifndef SNMP_IN_PORT
 #define SNMP_IN_PORT 161
+#endif
+/* The remote port the SNMP agent sends traps to. Most standard trap sinks won't
+   work if you change this! */
+#ifndef SNMP_TRAP_PORT
 #define SNMP_TRAP_PORT 162
+#endif
 
 #define SNMP_ES_NOERROR 0
 #define SNMP_ES_TOOBIG 1