Luxembourg:Network

Network: Global | Grenoble | Lille | Luxembourg | Lyon | Nancy | Nantes | Rennes | Sophia | Strasbourg | Toulouse

Network Topology

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  Automated Network topology from API

General overview

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Network Architecture

The Luxembourg site is built over two central network components:

• A Core Layer 2 / 3 switch of type Cisco Catalyst 6506E, including one single supervisor (VS-S720-10G) and two line Gigabit copper cards (WS-X6748-GE-TX). This Switch is connecting :
  • the 38 computing Nodes in 1GbE mode to the prod VLAN
  • the 38 computing Nodes in 1GbE mode to the admin VLAN
  • the NFS server (in both prod and admin VLAN)
  • the Adminfront server (in prod, admin, and nat VLAN)
  • the Renater backbone (VLAN 550)
• A server farm of type Cisco Nexus 5020, responsible for connecting the 22 computing nodes in 10GbE mode (VLAN hsc)

Connectivity to GRID5000

The connectivity to GRID 5000 is operated by the RESTENA foundation (for the luxembourgian side) in collaboration with Renater. The dedicated Grid5000 line has been prolongated from Nancy toward Luxembourg (see Global network map) via Esch/Elzette.

VLANs

Overview

VLAN	Name	Description	Network
VLAN 50	hsc	High speed computing network (10GbE)	192.168.14.0/23
VLAN 100	prod	Production network (all nodes ethernet interfaces + eth0 on each server/virtual machine)	172.16.176.0/20
VLAN 101	admin	Administration network (BMC interfaces + eth1 on each server)	172.17.176.0/20
VLAN 103	nat	NAT network	192.168.69.0/30
VLAN 550	Grid5000	Gateway to Grid5000/Renater 5	192.168.4.0/24
VLAN 1000	BLACKHOLE	local usage, unused ports	n/a

Network routing

VLAN prod: 172.16.176.0/20

• Computing nodes
  • granduc-eth0 (1GbE) 172.16.176.0/23
  • granduc-eth1 (1GbE) 172.16.178.0/23
  • granduc-eth2 (10GbE) 172.16.179.0/23
  • petitprince-eth0 (1GbE) 172.16.177.0/23
• Gateway: 172.16.191.254 (SUP720-10G)
• Servers 172.16.191.0/24
  • phys. eth0 (1GbE) 172.16.191.[1-99]
  • virtual eth0 (1GbE) 172.16.191.[100-199]

VLAN admin: 172.17.176.0/20

• Computing nodes
  • BMC: 172.17.176.0/23
• Gateway: 172.17.191.254 (SUP720-10G)
• Servers 172.17.190.0/23
  • BMC: 172.17.190.0/24
  • phys. eth1 (1GbE) 172.17.191.[1-99]
  • virtual eth1 (1GbE) 172.17.191.[100-199]

VLAN nat: 192.168.69.0/30

• Nat domU
  • eth0: 192.168.69.2
• Gateway: 192.168.69.1

The nat network is not routed on Grid5000, and is only available locally. The host 192.168.69.2 is the default gateway in the routing table of the core router.

VLAN hsc: 192.168.14.0/23

• Computing nodes
  • eth2 (10GbE): 192.168.14.0/23
• Gateway: 192.168.15.254 ( SUP720-10G DHCP Serveur)

The Core Switch (Cisco C6506E) is also acting as a DHCP Server for the Computing Nodes in the hsc VLAN. As the Nexus device is not DHCP Server capable, the hsc VLAN had been extended (using the interface 172.17.191.253 belonging to the admin VLAN on the nexus) to the Core switch which act as DHCP Server. The hsc segment is never routed among the network.

VLAN grid5000: 192.168.4.0/24

• Gateway (Luxembourg) : 192.168.4.21 ( SUP720-10G ), other site gateways: see Grid5000:Network

University of Luxembourg interconnection

We do not have an EXT VLAN on the site router. Instead, the adminfront has a link (eth3) on the University network (VLAN 124, 10.74.0.0/16). This interface is bridged and used by the NAT domU.