On Thu, Aug 22, 2013 at 5:24 PM, Theodore Elhourani <telho...@email.arizona.edu> wrote: > If the original packets are of length <= 1400, then they are successfully > transmitted through the tunnel. Only when a packet is greater than ~1480 it > gets dropped. You are right the ip stack is fragmenting the large packets, > but because some of them are a notch below 1500 they are passed as is. For > these packets, adding gre/ip headers would increase their size to > > 1500bytes. Subsequently they are dropped. The reason may be because the > packets are already beyond the ip stack of the host, and no further > manipulation of the packets is done after this point.
What version is this? If it is before 1.9 then setting header_cache=false in the tunnel options may help. > Reducing the size of packets, via MTU tweaking, seems to be a common > practice when gre is used. Any ideas on this ? Regardless of the outcome of the above, setting the MTUs to take into account the additional GRE headers will improve performance. _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
