AnsweredAssumed Answered

TCP/UDP Echo Server Example

Question asked by diz on Mar 19, 2012
Latest reply on Dec 2, 2014 by Clive One
did anybody try the TCP/UDP echo example from It compiles out of the box, and tcp echo works fine if tried first, but udp echo does not work for me (I am using a STM32F220G-EVAL board). When I try the echo tool which is included in the zip archive, mostly I don't get any answer, sometimes I get one answer and than nothing more.
Command and answers are:
echotool.exe /p udp /n 5

Hostname resolved as

Response time out
Response time out
Response time out
Response time out
Response time out

Statistics: Received=0, Corupted=0, Lost=5
When I get no replay, Wireshark shows ICMP messages "Destination unreachable (port unreachable)", despite the port 7 is correctly used in the example program.
TCP echo works as expected only if UDP was not tried first. When UDP was tried first, TCP echo becomes very slow (response times ~500-900 ms).
Any ideas?