Luxembourg:Network
Network Topology
Plans
General overview
PDF version: 
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
- 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.