Selected topics on network architecture and performance.
In my previous post on “OpenStack: MTU pitfalls with tunnels”, I mentioned the current difficulties in setting up an OpenStack overlay network with single-NIC compute nodes, which are caused by “mixing” native and encapsulated traffic on the same LAN. Also, I briefly sketched an idea to eliminate any MTU inconsistencies by splitting the external network into VLANs with different MTUs for native and encapsulated traffic.
(Read more...)This page provides some VLAN configuration tips for the setup described in my post “OpenStack VXLAN with single-NIC compute nodes”.
A great reference for the OVS VLAN configuration is the “Port TABLE” section of the ovs-vswitchd.conf.db(5) man page, which shows the VLAN-related port attributes (vlan_mode, tag, trunks), followed by a detailed description of the 4 VLAN modes (trunk, access, native-tagged, native-untagged) and the native VLAN concept.
(Read more...)Overlay tenant networks based on VXLAN and GRE tunnels have become extremely popular in OpenStack due to their flexibility and scalability.
(Read more...)