We have a problem where frames that pass through a Linux bridge do not reach the gateway outside of the mainframe box. We have set up an experiment that reproduces the problem, which looks like this:
(LINUX1) - <private vswitch> - (LINUXBR) - <public vswitch> - OSA - gateway The problem is that in this setup we cannot ping the gateway. But, under a different setup: (LINUX1) - <private vswitch> - (LINUXBR) - <public vswitch> - (LINUX2) Both LINUX1 and LINUX2 can communicate. Moreover, LINUX2 can ping the gateway (the OSA card is still connected to the public vswitch, I just did not put it in the picture). Some more details that may be important: - Both public and private vswitch are layer 2 - LINUXBR runs RHEL 6 and uses bridge-utils to create the bridge - private vswitch is not connected to any OSA card We have played with TCPDUMP and found that ARP (broadcast) packets do reach the gateway and come back, but ping's ICMP (unicast) packets get dropped. This led us to the following hypothesis: If there is a unicast packet originating from a MAC address not known to public vswitch, it gets dropped somewhere on the way between LINUXBR and the gateway. Does anyone know any settings that could affect filtering done either by the vswitch or by the OSA card? We asked our hardware people but they did not know of anything that could cause the problems. But a more targeted question could help if we knew what to ask for. Any debugging tips will be much appreciated. Thanks, Tomas Tomas Pavelka CA Technologies Sr Software Engineer Tel: +420226207796 [email protected] <mailto:[email protected]>[cid:[email protected]]<http://www.ca.com/> ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
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