Internal Network

Network topology

todo: create network topology diagram

Network segments

Overview

For performance and security reasons, the internal network is segmented into the logical domains listed below.

VLAN	Name	Network	Subdomain
10	SRV	10.10.10.0/24	srv.fablab.local
11	LAN	10.10.11.0/24	lan.fablab.local
13	GUEST	10.10.13.0/24	guest.fablab.local
-	VPN	10.10.23.0/24	vpn.fablab.local
69	ATELIER	10.10.69.0/24	atelier.fablab.local
99	MGMT	10.10.99.0/24	mgmt.fablab.local

Network segmentation is implemented via VLANs on the switch (layer 2: separation of collision domains) and separate IP subnets (layer 3: separation of broadcast domains)

Service Network (VLAN 10: "SRV")

Hosts:	Internal services such as file servers, printers etc
Connection:	Physical link to specific VLAN port
Access:	Clients (from LAN & WLAN segment) are granted access to services through firewall based on ruleset

flz-dns-01     10.10.10.10
flz-pos-01     10.10.10.11
flz-nas-01     10.10.10.12
flz-rpi-01     10.10.10.13

Client LAN (VLAN 11: "LAN")

Hosts:	Wired and wireless network clients, i.e. shared workstations, access switches, notebooks etc
Connection:	Access switches located across the FabLab or wireless connection to SSID "FabLab"
Access:	Anyone with physical access to FabLab and/or the wireless key

flz-cl-xx      10.10.11.100 - 199

Guest WLAN (VLAN 13: "GUEST")

Hosts:	External wireless network clients, i.e. visitor notebooks, smartphones
Connection:	Over the air: 2.4 and 5 GHz
Access:	Anyone in close proximity to FabLab
Restrictions:	Only allowed to connect to the internet, but no internal services

flz-gl-xx    10.10.13.100 - 199

VPN (VLAN -)

Hosts:	Admin access to FabLab network infrastructure
Connection:	OpenVPN connection to fireewall
Access:	Anyone with an OpenVPN profile and password
Restrictions:	Network and systems admins only

flz-gl-xx    10.10.13.100 - 199

Ateliergemeinschaft (VLAN 69: "ATELIER")

Hosts:	Ateliergemeinschaft in the former location of FabLab
Connection:	Physical link through wall behind the rack
Access:	Anyone with physical access to the Ateliergemeinschaft
Status:	Not yet implemented

tbd

Demilitarized Zone (VLAN 88: "DMZ")

Hosts:	Internet services like website test and dev environments, Diaspora pods, personal internet hosts etc
Connection:	Physical link to specific VLAN port
Access:	Internet and intranet access based on firewall ruleset
Status:	Not yet implemented

tbd

Management Network (VLAN 99: "MGMT")

Hosts:	Network equipment, server out-of-band management interfaces, serial console servers etc
Connection:	Physical link to specific VLAN port
Access:	Network and systems admins only

flz-fw-01     10.10.99.1
flz-fw-02     10.10.99.2
flz-sw-01     10.10.99.11
flz-sw-02     10.10.99.12
flz-ap-01     10.10.99.21

General network config

The gateway (i.e. the firewall) is always located at IP 10.10.x.1, and is currently also acting as the central DHCP, DNS and NTP server, as well as an Avahi (bonjour) proxy.

The various subnets are within the private 10/8 range defined by RFC 1918. The local supernet is 10.10/16, subnetted into various /24 networks.

The third octet of the address always corresponds to the VLAN ID of the respective network.

DHCP settings

Range:	10.10.[VLAN].100 - 199
Subnet mask:	255.255.255.0
Gateway:	10.10.[VLAN].1
DNS:	10.10.[VLAN].1
NTP:	10.10.[VLAN].1
Domain:	fablab.local (to make DNS entries unter .fablab.local directly accessible because Windows does not seem to properly respect domain search lists provided by DHCP)

DHCP service is provided on LAN, WLAN and GUEST (the latter getting assigned external nameservers)

DNS

The central DNS server, providing forward and reverse name resolution for the various internal networks is implemented using ISC bind running on the local firewall. In order to make things a bit easier, the internal domain fablab.local has DNS aliases (CNAMEs) pointing to the various servers, e.g. fablabnas.fablab.local is actually a DNS CNAME pointing to flz-nas-01.srv.fablab.local, the 'real' name of the NAS device. This way, clients can simply reach all services by using their hostnames (e.g. 'ping fablabnas')