On 10/27/2013 11:59 AM, Martinx - ジェームズ wrote:
Guys,
I am not detecting any problems related to "MTU = 1500" when using VXLAN!
It is easy to reproduce the "GRE MTU problem", when using GRE tunnels
with MTU = 1500, from a Instance, it is impossible to use RubyGems
(Ubuntu 12.04 Instance), for example, "gem install bundler" (neither
"bundle install" your RoR App) doesn't work with MTU 1500 on top of a
GRE tunnel, with MTU 1400 is fine.
But, now with VXLAN, I'm using MTU 1500 again without any problems!
Honestly, I don't know for sure if RubyGems changed too or, if it is
related to VXLAN being a bit better than GRE, anyway, I'll keep my
Havana cloud running with MTU 1500 from now on.
I'm not certain, but if you dig a little - either a tcpdump trace in one
of your instances, or a netperf -t TCP_STREAM -H <somewhere> -- -o
transport_mss, that in your VXLAN case you may be automagically getting
a TCP MSS that does not result in fragmentation/etc.
rick
_______________________________________________
Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
Post to : openstack@lists.openstack.org
Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
