From: chewygumstix <dan...@lm...> - 2008-12-03 21:25:28
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I'm running a system where Windows systems will be communicating back and forth with a gumstix via UDP multicast and am having a problem. I have a send test app and a receive test app that compile for linux and windows. When I run both applications on the gumstix they can communicate fine. Same goes if both on are Windows. I can also send udp packets from the gumstix and receive them in Windows. However I can't receive packets on the gumstix that were sent from Windows. I consider myself a novice when it comes to linux, so I'm probably doing something dumb. To get multicast to work as I have it now I had to do the following: iproute add 224.0.0.0/4 dev eth0 So I guess here are my questions: Is there something I need to do to enable receiving external udp multicast packets on the gumstix? And is there a command in linux to view packets being received on the gumstix? Thanks -- View this message in context: http://www.nabble.com/UDP-Mutlicast-Almost-Working-tp20821986p20821986.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Jeff S. <js...@ea...> - 2008-12-04 13:58:54
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chewygumstix wrote: > I'm running a system where Windows systems will be communicating back and > forth with a gumstix via UDP multicast and am having a problem. > > I have a send test app and a receive test app that compile for linux and > windows. When I run both applications on the gumstix they can communicate > fine. Same goes if both on are Windows. I can also send udp packets from the > gumstix and receive them in Windows. However I can't receive packets on the > gumstix that were sent from Windows. > > I consider myself a novice when it comes to linux, so I'm probably doing > something dumb. > > To get multicast to work as I have it now I had to do the following: > > iproute add 224.0.0.0/4 dev eth0 > > So I guess here are my questions: > Is there something I need to do to enable receiving external udp multicast > packets on the gumstix? > And is there a command in linux to view packets being received on the > gumstix? > > Thanks > > Does your messageing application handle byte order? Is the gumstick's processor a different endian than the windows box? I just happen to be working on a Spread Toolkit application and endianess is mentioned |
From: chewygumstix <dan...@lm...> - 2008-12-04 14:10:00
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Yeah it does. But I also have print statements that let me know as soon as I get any UDP message over the specified port and they don't get hit. -- View this message in context: http://www.nabble.com/UDP-Mutlicast-Almost-Working-tp20822056p20834093.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Dave H. <dhy...@gm...> - 2008-12-04 16:58:11
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Hi, > To get multicast to work as I have it now I had to do the following: > > iproute add 224.0.0.0/4 dev eth0 > > So I guess here are my questions: > Is there something I need to do to enable receiving external udp multicast > packets on the gumstix? > And is there a command in linux to view packets being received on the > gumstix? Something to double check. Network packets use big-endian port numbers and IP addresses. The gumstix and windows are both little-endian. So when you assign the ip address and port numbers in the packets being sent, you need to make sure that you're using the htonl and htons macros. I use wireshark under windows to monitor ethernet traffic. On the gumstix you can use tcpdump to print out captured packets. Using wireshark you should be able to see the captured packets. Examine them carefully and check the IP address and port and make sure that they're correct. -- Dave Hylands Shuswap, BC, Canada http://www.DaveHylands.com/ |
From: chewygumstix <dan...@lm...> - 2008-12-09 20:31:25
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chewygumstix wrote: > > > I'm running a system where Windows systems will be communicating back and > forth with a gumstix via UDP multicast and am having a problem. > > I have a send test app and a receive test app that compile for linux and > windows. When I run both applications on the gumstix they can communicate > fine. Same goes if both on are Windows. I can also send udp packets from > the > gumstix and receive them in Windows. However I can't receive packets on > the > gumstix that were sent from Windows. > > I consider myself a novice when it comes to linux, so I'm probably doing > something dumb. > > To get multicast to work as I have it now I had to do the following: > > iproute add 224.0.0.0/4 dev eth0 > > So I guess here are my questions: > Is there something I need to do to enable receiving external udp multicast > packets on the gumstix? > And is there a command in linux to view packets being received on the > gumstix? > > Thanks > > Ok, I'm still having the same problem but have a little more info... Here's output from tcpdump showing the same packet being received from the various machines. Which means the UDP packets are making it from Windows to the gumstix, but I notice that messages from Windows have the ID in the IP Header set, as well as DF (Don't Fragment) is set to false. Does this provide any more info that might point someone where the real problem lies? WINDOWS to Gumstix (does not get received by my socket) -7:-45:-2.015784 IP (tos 0x0, ttl 15, id 35331, offset 0, flags [none], proto: UDP (17), length: 444) 172.30.42.3.1165 > 239.255.183.180.47028: UDP, length 416 LINUX to GUMSTIX (does get received by my socket) -7:-43:-38.451991 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.13.32771 > 239.255.183.180.47028: UDP, length 416 GUMSTIX to GUMSTIX (does get received by my socket) -7:-33:-10.955608 IP (tos 0x0, ttl 15, id 0, offset 0, flags [DF], proto: UDP (17), length: 444) 172.30.42.110.1025 > 239.255.183.180.47028: UDP, length 416 -- View this message in context: http://www.nabble.com/UDP-Mutlicast-Almost-Working-tp20822056p20922533.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: chewygumstix <dan...@lm...> - 2008-12-10 20:50:01
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chewygumstix wrote: > > > I'm running a system where Windows systems will be communicating back and > forth with a gumstix via UDP multicast and am having a problem. > > I have a send test app and a receive test app that compile for linux and > windows. When I run both applications on the gumstix they can communicate > fine. Same goes if both on are Windows. I can also send udp packets from > the > gumstix and receive them in Windows. However I can't receive packets on > the > gumstix that were sent from Windows. > > I consider myself a novice when it comes to linux, so I'm probably doing > something dumb. > > To get multicast to work as I have it now I had to do the following: > > iproute add 224.0.0.0/4 dev eth0 > > So I guess here are my questions: > Is there something I need to do to enable receiving external udp multicast > packets on the gumstix? > And is there a command in linux to view packets being received on the > gumstix? > > Thanks > > -- > View this message in context: > http://www.nabble.com/UDP-Mutlicast-Almost-Working-tp20821986p20821986.html > Sent from the Gumstix mailing list archive at Nabble.com. > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win great > prizes > Grand prize is a trip for two to an Open Source event anywhere in the > world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > > this problem was solved with the follow call ifconfig eth0 allmulti I guess the netmicroSD-vx requires that flag for multicast. Odd thing is I have another Linux machine and this flag is not required. -- View this message in context: http://www.nabble.com/UDP-Mutlicast-Almost-Working-tp20822056p20943464.html Sent from the Gumstix mailing list archive at Nabble.com. |