Difference between revisions of "KaVLAN"

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== 3: Global VLAN ==
 
== 3: Global VLAN ==
  
''Global VLANs'' is a VLAN which spreads on all grid5000 sites (using IEEE 802.1ad encapsulation, also known as QinQ to provide a same layer 2 network for all sites). Therefore you can configure nodes of different sites on the same ''global VLAN''.
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''Global VLANs'' are VLANs which spread on all grid5000 sites (using IEEE 802.1ad encapsulation, also known as QinQ to provide a same layer 2 network for all sites). Therefore you can configure nodes of different sites in the same ''global VLAN'', i.e. in a same layer 2 network (Ethernet, no inter-site IP routing).
  
 
There is exactly 1 and only 1 ''global VLAN'' available by site. If it is already reserved by another user, you can try to get one from another site (reservation must be made on the site of the ''global VLAN'')
 
There is exactly 1 and only 1 ''global VLAN'' available by site. If it is already reserved by another user, you can try to get one from another site (reservation must be made on the site of the ''global VLAN'')

Revision as of 11:01, 20 January 2016

"KaVLAN scheme"
KaVLAN big picture

Overview

KaVLAN architecture: see local VLANs in green, routed VLANs in blue, global VLANs in purple and the default VLAN in red

KaVLAN provides network isolation capabilities for Grid'5000 users via a high-level, user-driven interface to 802.1q (VLAN). KaVLAN allows users to manage VLAN on their Grid'5000 nodes. The benefit is a complete level 2 isolation for users' experiments.

It is however important to note that KaVLAN does not guarantee performance isolation: on sites with a hierarchical network (such as Nancy), inter-switch links may indeed be shared between various VLANs/experiments.

KaVLAN is to be used together with OAR and Kadeploy to do experimentations involving network reconfiguration.

3 types of VLANs are available for users on Grid'5000:

KaVLAN name in OAR type first id last id
kavlan-local local 1 3
kavlan routed 4 9
kavlan-global global 10 21

See the 2 schemas on the right which illustrate KaVLAN architecture.

Please also note the installation status of KaVLAN for all Grid'5000 sites:

Sites Version Status
Grenoble 1.2.7-1 Check.png
Lille 1.2.7-1 Check.png
Luxembourg 1.2.7-1 Check.png
Lyon 1.2.7-1 Check.png
Nancy 1.2.7-1 Check.png
Nantes 1.2.7-1 Check.png
Rennes 1.2.7-1 Check.png
Sophia 1.2.7-1 Check.png

1: Local VLAN

An local VLAN is completely isolated from the rest of Grid'5000: no routing is configured. Therefore, you have to hop by a special host to reach your nodes inside that kind of VLAN.

Then you will be able to connect any of your nodes within the VLAN using hostnames such as hostname-X-kavlan-ID (adding the suffix -kavlan- + the VLAN_ID to the regular hostname), for instance from the SSH gateway of the VLAN. The hostname of that SSH gateway is: kavlan--ID.

The figure below shows two jobs using KaVLAN: each job has its nodes isolated in a local VLAN (purple and green). The other nodes are all in the default VLAN (red). The only way to reach the isolated nodes is to hop by the VLAN's SSH gateway machine (kavlan-1 and kavlan-2 in the figure). Technically speaking, the SSH gateway has two Ethernet interfaces: one in the default VLAN and one in the dedicated VLAN. An other way to reach an isolated node is to use the kaconsole command.

KaVLAN architecture: 2 jobs running KaVLAN
Note.png Note

Please mind that:

  • the SSH gateways are NOT providing IP routing: they are only intermediate machines for a SSH hop to the machines in the local VLANs.
  • as your nodes are isolated from the rest of Grid'5000, NFS mounts of /home partition is not possible. Therefore, Grid'5000 environments that mount /home partition (-nfs, -big, -prod) may fail to boot

2: Routed VLAN

Unlike local VLANs which are isolated, routed VLANs are not isolated at the layer 3: IP packets are routed. Therefore you can reach the nodes inside a routed VLAN from the rest of Grid5000 (e.g. from the default VLAN, or from another routed VLAN). No need here for a hop by a SSH gateway, as it is the case for local VLANs.

Nodes in the VLAN are reachable with the following hostname: hostname-X-kavlan-ID (same naming scheme as for local VLANs), from the frontends of the sites for instance.

3: Global VLAN

Global VLANs are VLANs which spread on all grid5000 sites (using IEEE 802.1ad encapsulation, also known as QinQ to provide a same layer 2 network for all sites). Therefore you can configure nodes of different sites in the same global VLAN, i.e. in a same layer 2 network (Ethernet, no inter-site IP routing).

There is exactly 1 and only 1 global VLAN available by site. If it is already reserved by another user, you can try to get one from another site (reservation must be made on the site of the global VLAN)

Since it is a same layer 2 network, no routing between the nodes which are placed in a global VLAN is required (even from site to site).

To reach nodes inside a global VLAN from outside, routing is configured on the router of the site where the global VLAN is reserved. Hostname for the nodes within the VLAN follow the same scheme as above: hostname-X-kavlan-ID.

Note.png Note

Please mind that there is not performance isolation in between all global VLANs ans also Grid'5000 inter-site VLAN (backbone VLAN). All share the same inter-site physical link

Reserving a VLAN

KaVLAN only works with deploy reservations; to obtain nodes and a VLAN, you must reserve kavlan resources (VLAN-IDs) with the oarsub command. There are 3 kinds of resources defined in OAR: kavlan, kavlan-local, kavlan-global. For example, if you need 3 nodes and a local VLAN, you can run:

Terminal.png frontend:
oarsub -t deploy -l {"type='kavlan-local'"}/vlan=1+/nodes=3 -I

Then you can get the ID of your VLAN using the kavlan command

Terminal.png frontend:
kavlan -V

If you need to run that command from outside the shell which is started by OAR for your reservation, you have to give the OAR JOBID.

Terminal.png frontend:
kavlan -V -j JOBID

Either ways, you should get an VLAN ID integer in the <1-3> range for local VLANs, <4-9> for routed VLANs, and greater than 10 for global VLANs (only one global VLAN ID is available per site, that should be the one of the site you are connected to).


See below the KaVLAN ID, and associated IP subnets (served by DHCP in the VLANs)

Local VLANs (non-routed)
Site KAVLAN-1 KAVLAN-2 KAVLAN-3
All 192.168.192.0/20 192.168.208.0/20 192.168.224.0/20
Routed VLANs
Site KAVLAN-4 KAVLAN-5 KAVLAN-6 KAVLAN-7 KAVLAN-8 KAVLAN-9
Bordeaux 10.0.0.0/18 10.0.64.0/18 10.0.128.0/18 10.0.192.0/18 10.1.0.0/18 10.1.64.0/18
Grenoble 10.4.0.0/18 10.4.64.0/18 10.4.128.0/18 10.4.192.0/18 10.5.0.0/18 10.5.64.0/18
Lille 10.8.0.0/18 10.8.64.0/18 10.8.128.0/18 10.8.192.0/18 10.9.0.0/18 10.9.64.0/18
Lyon 10.12.0.0/18 10.12.64.0/18 10.12.128.0/18 10.12.192.0/18 10.13.0.0/18 10.13.64.0/18
Nancy 10.16.0.0/18 10.16.64.0/18 10.16.128.0/18 10.16.192.0/18 10.17.0.0/18 10.17.64.0/18
Orsay 10.20.0.0/18 10.20.64.0/18 10.20.128.0/18 10.20.192.0/18 10.21.0.0/18 10.21.64.0/18
Rennes 10.24.0.0/18 10.24.64.0/18 10.24.128.0/18 10.24.192.0/18 10.25.0.0/18 10.25.64.0/18
Toulouse 10.28.0.0/18 10.28.64.0/18 10.28.128.0/18 10.28.192.0/18 10.29.0.0/18 10.29.64.0/18
Sophia 10.32.0.0/18 10.32.64.0/18 10.32.128.0/18 10.32.192.0/18 10.33.0.0/18 10.33.64.0/18
Reims 10.36.0.0/18 10.36.64.0/18 10.36.128.0/18 10.36.192.0/18 10.37.0.0/18 10.37.64.0/18
Luxembourg 10.40.0.0/18 10.40.64.0/18 10.40.128.0/18 10.40.192.0/18 10.41.0.0/18 10.41.64.0/18
Nantes 10.44.0.0/18 10.44.64.0/18 10.44.128.0/18 10.44.192.0/18 10.45.0.0/18 10.45.64.0/18
Note.png Note

At the end of each network, address x.x.x.253 is used by Kavlan server

Global VLANs
Site Global Vlan Subnet Router IP
Bordeaux KAVLAN-10 10.3.192.0/18 10.3.255.254
Grenoble KAVLAN-11 10.7.192.0/18 10.7.255.254
Lille KAVLAN-12 10.11.192.0/18 10.11.255.254
Lyon KAVLAN-13 10.15.192.0/18 10.15.255.254
Nancy KAVLAN-14 10.19.192.0/18 10.19.255.254
Orsay KAVLAN-15 10.23.192.0/18 10.23.255.254
Rennes KAVLAN-16 10.27.192.0/18 10.27.255.254
Toulouse KAVLAN-17 10.31.192.0/18 10.31.255.254
Sophia KAVLAN-18 10.35.192.0/18 10.35.255.254
Reims KAVLAN-19 10.39.192.0/18 10.39.255.254
Luxembourg KAVLAN-20 10.43.192.0/18 10.43.255.254
Nantes KAVLAN-21 10.47.192.0/18 10.47.255.254
IP subnet assignments for the sites within a global VLANs

A global VLAN is a /18 subnet (16382 IP addresses). It is split so that every site gets one /23 (510 ip) in the global VLAN address space.

Example for the global VLAN of Lille, KAVLAN-12, whose address space is 10.11.192.0/18:

  • Bordeaux: 10.11.192.110.11.193.254
  • Grenoble: 10.11.194.110.11.195.254
  • Lille: 10.11.196.110.11.197.254
  • Lyon: 10.11.198.110.11.199.254
  • Nancy: 10.11.200.110.11.201.254
  • Orsay: 10.11.202.110.11.203.254
  • Rennes: 10.11.204.110.11.205.254
  • Toulouse: 10.11.206.110.11.207.254
  • Sophia: 10.11.208.110.11.209.254
  • Reims: 10.11.210.110.11.211.254
  • Luxembourg: 10.11.212.110.11.213.254
  • Nantes: 10.11.214.110.11.215.254

(More info in the Network page)

Setting up the VLAN

Configuring the VLANs is done with the kavlan command.

All the options of the command can be show using --help, as follows:

# kavlan --help
Usage: kavlan [options]
Specific options:
    -i, --vlan-id N                  set VLAN ID (integer or DEFAULT)
    -C, --ca-cert CA                 CA certificate
    -c, --client-cert CERT           client certificate
    -k, --client-key KEY             client key
    -l, --get-nodelist               Show nodenames in the given vlan
    -e, --enable-dhcp                Start DHCP server
    -d, --disable-dhcp               Stop DHCP server
    -V, --show-vlan-id               Show vlan id of job (needs -j JOBID)
    -g, --get-vlan                   Show vlan of nodes
    -s, --set-vlan                   Set vlan of nodes
    -j, --oar-jobid JOBID            OAR job id
    -m, --machine NODE               set nodename (several -m are OK)
    -f, --filename NODEFILE          read nodes from a file
    -u, --user USERNAME              username
    -v, --[no-]verbose               Run verbosely
    -q, --[no-]quiet                 Run quietly
        --[no-]debug                 Run with debug output
    -h, --help                       Show this message
        --version                    Show version

So, once you have a kavlan job running, and know your vlan ID, you can use the kavlan to put some network interfaces of your nodes in your VLAN (and later, back into the default VLAN) at anytime during the lifetime of your job.

In case of a node with multiple cabled network interfaces, each of them can be used, with the following naming:

  • for the default interface: hostname-X-kavlan-ID
  • for other interfaces: hostname-X-ethY-kavlan-ID


A DHCP service is provided in all kinds of VLANs (local, routed and global): once you have put network interfaces of some nodes in a VLAN, you can down-up them, or restart the networking service (with kaconsole3 for instance, or using the '| at now + 1 minute' magic, to run the command asynchronously and overcome the network disconnection that will occur), or reboot the node (with kareboot3) in order to get a relevant IP for the VLAN.


If needed for your experiment, please note that the kavlan command allows to deactivate the DHCP service in a VLAN.


For local VLANs, you are also allowed to ssh to the VLAN's SSH gateway, which is named kavlan-ID.


Please look at the KaVLAN tutorials for examples of usage (look at the see-also box at the top of the page).