Now I'm testing a trivial UDP-based program with LVS, just a few bytes in the packet.
Wireshark on the director shows the size of UDP packet is 520 bytes, no overly large udp packet size message, and still I got "Destination unreachable" ICMP. I'm suspecting the network layer never pass these UDP packets to LVS... Wang On Thu, Nov 24, 2011 at 6:16 AM, Roger Littin <ro...@rlmedia.co.nz> wrote: > Hi Wang, > > I have had similar problems where the director thinks the packet size is > larger than mtu of the real server and sends back this message. > Do you see anything in wireshark to indicate this. Overly large udp packet > size? > > I think when the network layer hands off the packet to lvs, it may have > already reassembled any fragments and then when lvs hands it back to the > network layer, it is rejected because it is too large. > > Roger. > > On 24/11/2011, at 3:45 AM, wang yi wrote: > >> Yes, I tried to make my application listen to real IP / virtual IP / >> INADDR_ANY, not working. >> >> But I think the problem isn't that. >> As I mentioned in the original post, the LVS router seemed not >> delivering client packets to real servers, instead, it generated ICMP >> message(Destination unreachable), and the packets may be dropped. >> >> Wang >> >> On Wed, Nov 23, 2011 at 6:30 PM, Roger Littin <ro...@rlmedia.co.nz> wrote: >>> Hi, >>> >>> I think you need to set your application on the real servers to listen to >>> the udp port on all ip's or at least the real ip and then it needs to >>> respond to the client on the vip. >>> >>> Roger. >>> >>> On 23/11/2011, at 10:06 PM, wang yi wrote: >>> >>>> Hi, all >>>> I've set up LVS with DR mode for Apache, it worked OK. Then I set >>>> up another Virtual Service for an UDP based program on the same boxes, >>>> but it won't work. >>>> >>>> Running Wireshark on the director showed that it got the UDP >>>> packets from client, but responsed these packets with an ICMP message, >>>> Destination unreachable (Port unreachable) >>>> >>>> I cannot find any information about this. Anything special about >>>> UDP based program? >>>> Regards. >>>> Leo >>>> >>>> _______________________________________________ >>>> Please read the documentation before posting - it's available at: >>>> http://www.linuxvirtualserver.org/ >>>> >>>> LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org >>>> Send requests to lvs-users-requ...@linuxvirtualserver.org >>>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users >>> >>> >>> _______________________________________________ >>> Please read the documentation before posting - it's available at: >>> http://www.linuxvirtualserver.org/ >>> >>> LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org >>> Send requests to lvs-users-requ...@linuxvirtualserver.org >>> or go to http://lists.graemef.net/mailman/listinfo/lvs-users >>> >> >> _______________________________________________ >> Please read the documentation before posting - it's available at: >> http://www.linuxvirtualserver.org/ >> >> LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org >> Send requests to lvs-users-requ...@linuxvirtualserver.org >> or go to http://lists.graemef.net/mailman/listinfo/lvs-users > > > _______________________________________________ > Please read the documentation before posting - it's available at: > http://www.linuxvirtualserver.org/ > > LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org > Send requests to lvs-users-requ...@linuxvirtualserver.org > or go to http://lists.graemef.net/mailman/listinfo/lvs-users > _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org Send requests to lvs-users-requ...@linuxvirtualserver.org or go to http://lists.graemef.net/mailman/listinfo/lvs-users