Network

👻 This page should document some bits of the network infrastructure of Kanthaus. Please maintain so people with a bit of network knowledge can understand and maintain the network. See also Server.

Overview

ISP

We currently use Telekom as our internet provider. They have a help page for diagnosing internet issues from their side: good idea to check this first if the wifi networks are still up, but not connected to the internet.

TRUNK network

the backbone of our network, connecting all Access Points and the central firewall, carries all the different networks via VLAN:

VLAN-ID	IP Range	Name	Purpose / Devices
untagged	192.168.178.x	ADMIN	configuration tnterfaces of all AP’s & Switches
4	192.168.4.x	PRINTER	connection between print server (kanthaus-server) and printer
5	192.168.5.x	IOT (former SMA)	only access to kanthaus-server and potentially whitelisted internet IP’s + isolated clients¹
100	192.168.100.x	RESTRICTED	normal internet access + isolated clients¹
101	192.168.101.x	VPN	tunneled to VPN (currently NL)
102	192.168.102.x	UNSECURE	normal internet access

¹ client isolation does not work between LAN <-> LAN clients

Wifis

SSID	Network	Encrypt.	802.11r	802.11w	Isolation	Comment
kanthaus	RESTRICTED	WPA3	-¹	required	on
kanthaus-insecure	INSECURE	WPA2	-	-	-	unsupported drivers, LAN parties, etc.
kanthaus-gast	VPN	-	-	-	on
kh-admin	ADMIN	WPA3	-	required	-
kh-iot	IOT	WPA2	-	-	on

802.11r: Fast Roaming 802.11w: Management Frame Protection

¹ would be cool to have it on, but eventually led to issues. let’s reevaluate in a few months

Device list

Type	Name	Admin-IP	Location	Hardware	Comments
Router	fritz.box	192.168.200.1	K20-1 hallway	FritzBox 7530	DSL termination (on main network), telephone
Router	firewall	192.168.178.1	K20-B rack		central router / firewall
AP	dragon-k20-0	192.168.178.207	K20-0 hallway	Archer C5 v1.2	switch with servers
AP	dragon-k20-1	192.168.178.201	K20-1 hallway	Archer C5 v1.2	maybe overloaded
AP	dragon-k20-3	192.168.178.208	K20-3 center	Archer C5 v1.2
AP	dragon-k20-B	192.168.178.206	K20-B water room	Archer C5 v1.2	for IoT devices
AP	dragon-k22-1 ?	192.168.178.202 192.168.178.217	K22-1 hallway	Archer C5 v1.2	Timber installed the "normal" firmware, now it has a separate wifi (see Mattermost)
AP	dragon-k22-2	192.168.178.203	K22-2 hallway	Archer C5 v1.2	maybe overloaded
Managed Switch	k20 firewall switch	192.168.178.9	K20-B rack	TL-SG108E
Managed Switch	k22 trunk switch	192.168.178.10	K22-B stairs	GS108E v3
Switch	k20 trunk switch	-	K20-B Rack		provides PoE for some AP’s in K20
Server	kanthaus-server	192.168.*.2	K20-0 hallway	Server, i5-2500K, 16GB Ram	file storage, nextcloud, foodsharing gitlab CI Server, housebus logging & time/sunset provider (see Repo)
Main water meter reader	mainwatermeter	192.168.5.37	K20 basement (former heating room)	ESP32-CAM	see [[./water.html|Water usage tracking]]
Warm water meter reader	warmwatermeter	192.168.5.38	K20 basement (rainwater room)	ESP32-CAM	see [[./water.html|Water usage tracking]]
Ventilation watcher	ventilation	192.168.5.39	K20 attic	ESP32-WROOM	see docs
K20 door	k20-door	192.168.5.40	K20 hallway	ESP32-CAM	see docs
radiator fan switch	socket-radiator-fansipan	192.168.5.41	Fansipan	LSPA9/CB2S/BK7231N
radiator fan switch	socket-radiator-elephant	192.168.5.42	Elephant Room	LSPA9/CB2S/BK7231N
electricity monitor	socket-2-k22-3-aircon	192.168.5.43	K22-3	LSPA9/CB2S/BK7231N

Firewall / Router

Central point of all subnets, routes between them

• runs OPNSense
• due to lack of ports on firewall, a VLAN switch added, bound to the firewall, also connecting to the fritz!box
• Features:
  • VPN client
  • DNS Server
  • DHCP Server

Access Points

• see Device list
• so far all Archer C5 v1.2
• centrally configured by OpenWISP: https://openwisp.im.kanthaus.online (only reachable inside the ADMIN net)
• starting point for other ethernet cables on that floor
• in K20 all powered by PoE (802.3af) from the switch in the basement

Printer (Canon C2025i)

• Printer is in its own subnet together with the kanthaus-server
• On the kanthaus-server, there is CUPS running with printer sharing and auto discovery in the networks via avahi-daemon
• In RESTRICTED and UNSECURE the printer is also reachable directly via 192.168.4.153:9100

kanthaus-server

• Most of the services are running inside a docker-compose setup
  • Repo: https://git.kanthaus.online/kanthaus/kanthaus-server-services
  • in /opt/kh-services
  • checking state: docker-compose ps
  • starting everything: docker-compose up -d
  • logs: docker-compose logs -f --tail=20
• BTRFS raid for HDD’s under /data

Random notes

Building customized OpenWRT for Archer C5

ssh kanthaus-server
sudo -iu openwrt-builder
cd openwrt
make
ls -l bin/targets/ath79/generic/

included changes

• root password
• default IP 192.168.178.200 in ADMIN range
• switch: all ports in ADMIN net
• disabled DNS rebind protection
• wireless interface names
• additional packages
  • openwisp-config
  • prometheus-node-exporter-lu
  • luci-ssl (for https)
  • ebtables (for effective client isolation)
  • tcpdump (for easier debugging)

Upgrading customized OpenWRT

Documentation: https://openwrt.org/docs/guide-developer/toolchain/use-buildsystem

ssh kanthaus-server
sudo -iu openwrt-builder
cd openwrt
git pull
git checkout v23.05.2

Edit feeds.conf to change the branch for each feed to the new version, e.g. ...;openwrt-23.05

./scripts/feeds update -a
./scripts/feeds install -a
make -j4 defconfig download clean world
ls -l bin/targets/ath79/generic/

Errors during make world are to be expected, usually the set of default packages changed and dependency conflicts are happening. Investigate generated the .config file and compare with the official ones at https://downloads.openwrt.org/releases/23.05.2/targets/ath79/generic/config.buildinfo

How to update OPNsense

There is a short downtime involved during the two reboots, usually 2 minutes each.

1. Join the kanthaus-admin wifi network and log in to 192.168.178.1 (user root, password in keepass). Export the configuration to make a backup.
2. Check if updates are available (System->Firmware->Updates)
3. In case of minor updates, just use the button to perform
4. If there is a major update (2x per year), download the newest version from https://opnsense.org/download/, unzip and flash to any USB stick
5. Take a VGA monitor, a USB keyboard and the USB stick to the K20 basement big room, open the rack box and connect the devices to the small computer (HP)
6. Log in with the USB keyboard (same credentials as above) and trigger a reboot. It should now boot from the USB stick.
7. Press any key when it prompts to run the “Importer”. Now it will boot up a live environment and read the configuration file. If successful, network services should run as before.
8. If all looks good, it’s time to install to disk. Run opnsense-installer from the shell (either on local keyboard or via ssh), choose ZFS and let the installer do its job.
9. Remove the USB stick and reboot again.
10. Check if the system came up good.
11. Perform any last updates from the web UI.
12. Delete the configuration backup again, it can contain secrets.
13. Check if os-realtek-re is installed
14. Check if VPN for kanthaus-gast is online

Pitfalls

• We use 802.1q VLAN tagging. All switches everywhere need to have at least passive passthrough support, otherwise the Vlans disappear at that switch. I don’t know of any gigabit switch that does not support this.
• Again Vlan: Managed switches normally need to have all VLANs that should be forwarded (also tagged -> tagged forward) defined in them.
• Again Vlan: Some Access Points like WDR841 v7/v8 cannot handle tagged and untagged vlan on the same port at the same time. So far, we don’t have any equipment like that and likely we will never have, but just to know…
• Again Vlan: fritz boxes have their switch in managed vlan mode and don’t forward any tagged vlan