Charles, My instinct would be to run a packet trace. Use PROT=UDP,PORTNUM=port and DISCARD=ALL. (DISCARD is a newish feature that will trace packets that are about to be dropped by the stack.)
Good luck, Steven St.Jean > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Charles Mills > Sent: Tuesday, March 19, 2013 3:16 PM > To: [email protected] > Subject: Lost datagrams on z/OS 1.12? > > I've got a problem that is defying my ability to find it. I have a product > that uses sendto() to send UDP messages (datagrams). At one and perhaps > two z/OS 1.12 customers I have seen a problem in which what appear to be > perfectly good sendto()'s send a datagram that never arrives at its > destination. (Of course, the lack of error feedback is a known > characteristic of UDP.) > > Version x.1 of my product does not exhibit this behavior. Version x.2 > does. > There is relatively little difference between how the two issue sendto(). > I have never seen the problem on my development machine, including under > z/OS 1.12. > > It is definitely not a firewall or other external issue because Version > x.1 works fine. You bring it down and bring Version x.2 up with the same > parameters and it works for a little while and then 100% of the messages > start disappearing. You bring it down and bring x.1 back up and all is > well. > Similar TCP/IP code does not seem to have the same problem. > > Yes, obviously it could be your basic program bug and I am of course > working the heck out of that angle. I'm not asking this list to debug code > it has not seen. The code is way too complex to post here meaningfully. > > But does this problem ring a bell with anyone? I am not the most skilled > in the world at searching for APARs. Does anyone else want to spend 5 > minutes and see if you can find anything? > > Thanks much, > Charles > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email > to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
