diff --git a/RELEASE.txt b/RELEASE.txt
index 51e24088a..80948afad 100755
--- a/RELEASE.txt
+++ b/RELEASE.txt
@@ -96,6 +96,7 @@ This document describes the differences between v7.0.0 and v6.x.x
 - m3 fix for gain caps to invert where needed when loading from trimbit file (fix for feature might have been added only in developer branch)
 - pat loop and wait address default
 - ctb and moench Fw fixed (to work with pattern commdand) )addreess length
+- setting rx_hostname (or udp_dstip with rx_hostname not none) will always set udp_dstmac. solves problem of chaing udp_dstip and udp_dstmac stays the same
 - jungfrau reset core and usleep removed (fix for 6.1.1 is now fixed in firmware)
 
 
diff --git a/python/slsdet/detector.py b/python/slsdet/detector.py
index c852f080c..27823ec5d 100755
--- a/python/slsdet/detector.py
+++ b/python/slsdet/detector.py
@@ -1182,6 +1182,7 @@ class Detector(CppDetectorApi):
         ----
         Not mandatory to set as udp_dstip retrieves it from slsReceiver process but must be set if you use a custom receiver (not slsReceiver). \n
         To set MACs for individual modules, use setDestinationUDPMAC. 
+        Use router mac if router between detector and receiver.
         
         Example
         -------
@@ -1208,6 +1209,7 @@ class Detector(CppDetectorApi):
         To set MACs for individual modules, use setDestinationUDPMAC2. \n
         [Jungfrau] bottom half \n
         [Gotthard2] veto debugging \n
+        Use router mac if router between detector and receiver.
         
         Example
         ------
diff --git a/slsDetectorSoftware/include/sls/Detector.h b/slsDetectorSoftware/include/sls/Detector.h
index 2b900c92f..a1f851e12 100644
--- a/slsDetectorSoftware/include/sls/Detector.h
+++ b/slsDetectorSoftware/include/sls/Detector.h
@@ -743,7 +743,8 @@ class Detector {
 
     /** Mac address of the receiver (destination) udp interface. Not mandatory
      * to set as setDestinationUDPIP (udp_dstip) retrieves it from slsReceiver
-     * process but must be set if you use a custom receiver (not slsReceiver).
+     * process but must be set if you use a custom receiver (not slsReceiver).\n
+     * Use router mac address if router in between detector and receiver.
      */
     void setDestinationUDPMAC(const MacAddr mac, Positions pos = {});
 
@@ -751,10 +752,11 @@ class Detector {
     Result<MacAddr> getDestinationUDPMAC2(Positions pos = {}) const;
 
     /* [Jungfrau][Gotthard2] Mac address of the receiver (destination) udp
-    interface 2. \n Not mandatory to set as udp_dstip2 retrieves it from
-    slsReceiver process but must be set if you use a custom receiver (not
-    slsReceiver). \n [Jungfrau] bottom half \n [Gotthard2] veto debugging \n
-    */
+     * interface 2. \n Not mandatory to set as udp_dstip2 retrieves it from
+     * slsReceiver process but must be set if you use a custom receiver (not
+     * slsReceiver). \n [Jungfrau] bottom half \n [Gotthard2] veto debugging \n
+     * Use router mac address if router in between detector and receiver.
+     */
     void setDestinationUDPMAC2(const MacAddr mac, Positions pos = {});
 
     Result<int> getDestinationUDPPort(Positions pos = {}) const;
diff --git a/slsDetectorSoftware/src/CmdProxy.h b/slsDetectorSoftware/src/CmdProxy.h
index 2c252f57a..45ce37247 100644
--- a/slsDetectorSoftware/src/CmdProxy.h
+++ b/slsDetectorSoftware/src/CmdProxy.h
@@ -1631,7 +1631,8 @@ class CmdProxy {
         "[x:x:x:x:x:x]\n\tMac address of the receiver (destination) udp "
         "interface. Not mandatory to set as udp_dstip retrieves it from "
         "slsReceiver process, but must be set if you use a custom receiver "
-        "(not slsReceiver).");
+        "(not slsReceiver). Use router mac if router between detector and "
+        "receiver.");
 
     INTEGER_COMMAND_VEC_ID(
         udp_dstmac2, getDestinationUDPMAC2, setDestinationUDPMAC2, MacAddr,
@@ -1639,8 +1640,8 @@ class CmdProxy {
         "udp interface 2. Not mandatory to set as udp_dstip2 retrieves it from "
         "slsReceiver process but must be set if you use a custom receiver (not "
         "slsReceiver). \n\t [Jungfrau] top half or inner interface \n\t "
-        "[Gotthard2] veto "
-        "debugging.");
+        "[Gotthard2] veto debugging. Use router mac if router between detector "
+        "and receiver.");
 
     INTEGER_COMMAND_VEC_ID_GET(
         udp_dstport, getDestinationUDPPort, setDestinationUDPPort,
diff --git a/slsDetectorSoftware/src/Module.cpp b/slsDetectorSoftware/src/Module.cpp
index 77c35b671..a6da1f2de 100644
--- a/slsDetectorSoftware/src/Module.cpp
+++ b/slsDetectorSoftware/src/Module.cpp
@@ -1320,16 +1320,16 @@ void Module::setReceiverHostname(const std::string &receiverIP) {
     MacAddr retvals[2];
     sendToReceiver(F_SETUP_RECEIVER, retval, retvals);
     // update Modules with dest mac
-    if (retval.udp_dstmac == 0 && retvals[0] != 0) {
-        LOG(logINFO) << "Setting destination udp mac of "
-                        "Module "
-                     << moduleIndex << " to " << retvals[0];
+    if (retvals[0] != 0) {
+        LOG(logINFO) << "Setting destination udp mac of Module " << moduleIndex
+                     << " to " << retvals[0]
+                     << ". Use udp_dstmac for custom mac.";
         sendToDetector(F_SET_DEST_UDP_MAC, retvals[0], nullptr);
     }
-    if (retval.udp_dstmac2 == 0 && retvals[1] != 0) {
-        LOG(logINFO) << "Setting destination udp mac2 of "
-                        "Module "
-                     << moduleIndex << " to " << retvals[1];
+    if (retvals[1] != 0) {
+        LOG(logINFO) << "Setting destination udp mac2 of Module " << moduleIndex
+                     << " to " << retvals[1]
+                     << ". Use udp_dstmac2 for custom mac.";
         sendToDetector(F_SET_DEST_UDP_MAC2, retvals[1], nullptr);
     }