Network update part 3: Network segregation2018-05-20 [ networking ]
You can find the fancy DOT file here.
The main idea was to segregate devices that do not need to talk to each other to avoid potential security risks. Most stuff is in the 'server' VLAN now, and it doesn't really make sense to access it directly, as we have access via an nginx reverse proxy that does SSL termination.
My first step was to first move everything into their respective VLANs:
On the router I simply added these lines to my
iface lan0.10 inet static address 192.168.10.1 netmask 255.255.255.0 iface lan0.20 inet static address 192.168.20.1 netmask 255.255.255.0 iface lan0.30 inet static address 192.168.30.1 netmask 255.255.255.0 iface lan0.40 inet static address 192.168.40.1 netmask 255.255.255.0 iface lan0.50 inet static address 192.168.50.1 netmask 255.255.255.0
ifup for every interface.
On the server I added something similar (but with bridges):
# wifi iface enp8s0.10 inet manual auto vmbr10 iface vmbr10 inet static address 192.168.10.10 netmask 255.255.255.0 gateway 192.168.10.1 bridge_ports enp8s0.10 bridge_stp off bridge_fd 0 bridge_vlan_aware yes nameserver 192.168.10.1
(repeated 5 times with matchin VLANs)
In the shorewall
interfaces file I added:
wifi lan0.10 dhcp,tcpflags=0,nosmurfs srv lan0.20 dhcp,tcpflags=0,nosmurfs guest lan0.30 dhcp,tcpflags=0,nosmurfs bnet lan0.40 dhcp,tcpflags=0,nosmurfs dmz lan0.50 dhcp,tcpflags=0,nosmurfs
snat file I also added my networks.
MASQUERADE 169.254.0.0/16,\ 192.168.2.0/24,\ 192.168.10.0/24,\ 192.168.20.0/24,\ 192.168.30.0/24,\ 192.168.40.0/24,\ 192.168.50.0/24 wan
zones file I added:
wifi ipv4 srv ipv4 bnet ipv4 guest ipv4 dmz ipv4
The idea of this setup was to remove un-needed access to everything, so I started by removing external access to everything I could think of:
## Deny NTP and DNS to the internet, we serve our own and advertise it via DHCP NTP(REJECT) loc net DNS(REJECT) loc net
This implicitly left:
- srv, bnet and dmz without any connectivity at all
Allowing what's needed
As stated in the image, I needed some connection between the VLANs:
- lbalancer -> rproxy tcp on port 80
- sonarr, twitch -> Internet(http, 80 and 443)
- rproxy -> sonarr (as we access sonarr via the lbalancer even internally)
I (unsuprisingly!) ran into some issues, even though in theory everything should be OK:
- Certain devices don't give a shit. Chromecast ignores the NTP server assigned by the DHCP server.
- Madsonic (service I use to self host music) requires internet access to start (!!). They are downloading
xsdfiles from both
java.sun.com. Without these files, Madsonic refuses to start. After this issue I'll look for another music player.
- I am currently having an issue routing from
rproxy(VLAN 20) to the physical server on it's untagged interface.
- If I connect from
rproxy(20) to server(20) then it works fine (via the linux virtual bridge, never reaches the router)
- Otherwise packets are being dropped, even though the router sees them.
- If I connect from
NTP for chromecast:
DNAT wifi loc:192.168.2.1 udp 123
I just map any NTP request coming from
wifi to my NTP server
Unable to route
I added IP for the physical server (VLAN 20) in
/etc/hosts for the
rproxy container, which makes it "work".
I left quite a lot of things with access to the internet, I'll write a follow up post detailing how I closed each one of them. For now the list is:
- Jenkins: ssh out, used to update git repos. http out: used by a Docker image to put images in S3.
- Madsonic (detailed above)
- Sonarr http out
- Twitch http out (this is a custom twitch broadcaster I wrote so I can watch the same stream all over the house)
- Router has full internet access (testing + repositories)
- Grafana is trying to reach
grafana.com(http) looking for updates for plugins or somesuch.
- Pip is broken on all hosts!
Bookscannot connect to IRC anymore.
- For HTTP I'll use a simple proxy which will be in the DMZ (Also useful for pip).
- For SSH I'll simply add a
tcpproxyinstance which will map 1:1.
- I'll have to investigate the IRC protocol to proxy it (and DCC) which is core for my