Quoting Andreas Hasenack ([email protected]): > Hi, > > I'm not sure where or how this should be fixed. > > I have a case where openstack was juju deployed with neutron networking, > and we needed to set instance-mtu = 1454 in the neutron-gateway charm. > > Instances launched in the cloud get that 1454 MTU set in their eth0 devices > and life is good. > > If, however, I create a container inside an instance (for example, via juju > deploy --to lxc:0), that container gets eth0 set with an MTU of 1500. And > that makes almost all connections stall, and the deployment fails. > > Now, who should set the default MTU for containers to be 1454 in this case? > Or, more explicitly, to mimic the MTU of the "host" (in this case, the > instance)? juju? lxc-create?
Hi, Does adding lxc.network.mtu = 1454 to /etc/lxc/default.conf on the instance before the containers are created fix the issue? Setting the mtu automatically in lxc is in general a good idea, but it won't catch all cases and may not catch yours. Are you using lxcbr0, or a br0 with eth0 bridged to it? (Actually if using lxcbr0 then I'd like to think that the kernel would fragment the lxcbr0 traffic has it hits your eth0 which would just slow your traffic down) -serge -- ubuntu-server mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-server More info: https://wiki.ubuntu.com/ServerTeam
