networking-notes

[Dmitriy Novakovskiy]

Currently there's a number of networking architecture diagrams and explanations available in MOS/Fuel docs, but "all of them are more of less ugly, outdated, and wrong" (c) not me. It would be nice if Docs team could review and fix (or redo) them. My wishlist for what I'd like to see in diagrams is below:

- List (legend) + scheme of all logical networks with following info:
-- What it's used for
-- How is it implemented (OVS bridge + name, VLAN/untagged/native VLAN)
-- How bridges are interconnected and mapped to eth/bond interfaces
- Examples of how user can map logical networks to physical NICs (2 typical setups - 2 NICs per server, 4 NICs per server)
- Hacks and temporary solutions (like Ceph public traffic going through br-mgmt)

It's quite possible that >2 diagrams are needed. OVS bridges are interconnected differently in VLAN and GRE modes. Also, physical and logical network perspective may be hard to fit on a single drawing.

Last but not least, I suggest that it's time to make an effort and make all terminology consistent across fuel-library, Fuel UI and documentation. For example:

Example 1:

There's a network called Private on "Configure interfaces" screen. The same network is called "Internal" on "Networks" screen and in documentation. Finally, in documentation http://docs.mirantis.com/openstack/fuel/fuel-6.0/reference-architecture.html the following explanation is provided: "The internal network connects all OpenStack nodes in the environment. All components of an OpenStack environment communicate with each other using this network. This network must be isolated from both the private and public networks for security reasons". This is COMPLETELY inaccurate - Internal (or "Private", which is more accurate) network is mapped to br-int bridge and is used to put VLAN tagged traffic from private tenant networks on physical ethX interface.

Example 2:

Storage network is explained by the following piece:

"Storage Network

Part of a cluster's internal network. It is used to separate storage traffic (Swift, Ceph, iSCSI, etc.) from other types of internal communications in the cluster. The Storage network is usually on a separate VLAN or interface, isolated from all other communication.". The description is vague and mostly wrong. In current implementation Storage network should be called Storage Replication, it carries only replication traffic from Ceph or Swift. Ceph public traffic, in turn, is dispatched through br-mgmt (so, goest through Management network) - while this is not fixed in Product this should be clearly explained in documentation.

Also, none of the diagrams outline Ceph, only "Cinder node".

[Dmitriy Novakovskiy (dnovakovskiy)]

My take on networking diagram + explaining legend (also not perfect and not entirely accurate) can be found here - https://docs.google.com/a/mirantis.com/drawings/d/1AREI2rIoEYDpg1sWxtPvAKNXEVIsYhrhMqaysE3bAKI/edit

[Irina Povolotskaya (ipovolotskaya)]

I could take up updating OVS+GRE and OVS+VLAN (legend, physical and logical networks).
Terminology requires more attention, so let's focus on topologies right now.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/152054

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/153492

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/152054
Committed: https://git.openstack.org/cgit/stackforge/fuel-docs/commit/?id=1075769abad8844cc1cd2b85645524fe26028558
Submitter: Jenkins
Branch: master

commit 1075769abad8844cc1cd2b85645524fe26028558
Author: Irina Povolotskaya <email address hidden>
Date: Mon Feb 2 12:14:00 2015 +0300

    Updates ref arch schemes for OVS+GRE, OVS+VLAN

    The following schemes should be updated as follows:
    * OVS+GRE - add legend, add description for GRE,
    create physical connection scheme
    * OVS+VLAN - add legend, create physical connection scheme

    Change-Id: Ie7c6e9a0871dd611b410ae8fb1e925d09d2334ff
    Closes-Bug: 1415904

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/153492
Committed: https://git.openstack.org/cgit/stackforge/fuel-docs/commit/?id=64c262919acfc1d4311566af47dca44d31f13f9d
Submitter: Jenkins
Branch: master

commit 64c262919acfc1d4311566af47dca44d31f13f9d
Author: Irina Povolotskaya <email address hidden>
Date: Fri Feb 6 11:46:15 2015 +0300

    Updates networking terms from Ops Guide

    Since some network descriptions provide inaccurate information,
    they should be updated with the actual one.

    Note that topologies are covered within
    another commit.

    Change-Id: Ic04d299efcfbede7e8eec2b5e55284ef14a65285
    Closes-Bug: 1415904