# UDP OUT - no output on wireshark

**URL:** <https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032>\
**Category:** Developing Nodes\
**Tags:** docker, function-node\
**Created:** [4 August 2022 19:21 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032 "2022-08-04T19:21:27Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![RBSI](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@RBSI](https://discourse.nodered.org/u/RBSI)\
**Post date:** [4 August 2022 19:21 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/1 "2022-08-04T19:21:28Z")

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![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/0/d/0d2724ce8d0c84630cb1ee774275202f830006c6.png)

Hello everyone.

I am trying to send a network variable list to a device (WAGO-PFC200) on port 1000, however i do not see any data transmission or receive on port 1000 via wireshark and here is more details on my format array node:

> var msg\_o = {};
> 
> var xOUTPUT\_NVL2 = 1;
> 
> //forcing a constant value  
> var arr = [["xOUTPUT\_NVL2","BOOL",xOUTPUT\_NVL2]];
> 
> msg\_o.payload = arr;
> 
> return msg\_o;

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**Author:** ![edje11](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/edje11/32/572_2.png) [@edje11](https://discourse.nodered.org/u/edje11)\
**Post date:** [4 August 2022 20:22 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/2 "2022-08-04T20:22:51Z")

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Is Wireshark running on the same pc as NR is running?  
If not do you have a switch with an monitor output to monitor other ports or maybe an oldskool hub?  
Wireshark can only sniff network traffic that's meant for the ipaddress from the machine where Wireshark is running on. Or you need a switch/router with a monitor port.

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**Author:** ![RBSI](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@RBSI](https://discourse.nodered.org/u/RBSI)\
**Post date:** [4 August 2022 20:41 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/4 "2022-08-04T20:41:27Z")

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yes wireshark is running on the same pc. The other device where node-red is running is and yes i am using a network switch with a monitor port to monitor what is happening.

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/9/3/931550f44451447345dd0984ee9b1950248c58f0.png)

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**Author:** ![craigcurtin](https://avatars.discourse-cdn.com/v4/letter/c/94ad74/32.png) [@craigcurtin](https://discourse.nodered.org/u/craigcurtin)\
**Post date:** [6 August 2022 01:33 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/5 "2022-08-06T01:33:31Z")

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Is NR running as a user with permissions to send on low port numbers (less than 1024 ?)

Are you runnnig this in Windows or Linux ?

Craig

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**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [6 August 2022 06:26 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/6 "2022-08-06T06:26:29Z")

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If you put a separate debug node attached to the net-var sender node, what do you see in the debug window?

Also, show us the settings of your UDP node

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [5 October 2022 06:27 UTC](https://discourse.nodered.org/t/udp-out-no-output-on-wireshark/66032/7 "2022-10-05T06:27:07Z")

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