Difference between revisions of "User:John/FreedomBox/Network architecture"

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#* we could offer to auto-detect public IP address
 
#* we could offer to auto-detect public IP address
 
# configure our local Bind9 service:
 
# configure our local Bind9 service:
## with DNS resolver nominated above
+
## with DNS resolver nominated above (1.1.1.1)
 
## with an A record for 'fbx.example.com' to point to 192.168.0.2
 
## with an A record for 'fbx.example.com' to point to 192.168.0.2
 
# configure our Bind9 resolver on the LAN:
 
# configure our Bind9 resolver on the LAN:
## tell user to configure broadband router DHCP server with DNS server 192.168.0.2
+
## tell user to configure DNS proxy to point to 192.168.0.2
## tell user to configure non-DHCP hosts with DNS server 192.169.0.2
+
## tell user to configure broadband router DHCP server with DNS server 192.168.0.1 (that's probably current default)
 +
## tell user to configure non-DHCP hosts with DNS server 192.169.0.1 (that's probably current default)
 
## tell user to add /etc/hosts (or equiv) for <code>192.168.0.2 fbx.example.com</code> for any LAN hosts not using our Bind9 resolver (ideally there are no such hosts)
 
## tell user to add /etc/hosts (or equiv) for <code>192.168.0.2 fbx.example.com</code> for any LAN hosts not using our Bind9 resolver (ideally there are no such hosts)
 +
##* if hosts file is being used instead of DNS this might affect alias configurations if those are added later on, ideal the LAN DNS will be used in preference to hosts files
  
 
== User wants to register their fbx on a new domain name on their static home IP address ==
 
== User wants to register their fbx on a new domain name on their static home IP address ==

Revision as of 09:47, 3 September 2020

Some notes about fbx network architecture.

Examples

In the following examples these configuration settings are used:

Setting Value
User's internet router LAN IP 192.168.0.1
User's LAN subnet mask 255.255.255.0
User's LAN config web client IP 192.168.0.37
User's fbx LAN DHCP IP 192.168.0.123
User's fbx LAN static IP 192.168.0.2
User's domain name example.com
User's FreedomBox name fbx.example.com
User's public IP address 139.218.130.78
User's internet DNS resolver 1.1.1.1

Use case

User wants to register their fbx on their existing domain name on their static home IP address

Prerequisites:

  • user has a domain name registered (example.com)
  • user has DNS hosting and nameservers configured
  • user has access to do web based configuration of their DNS settings
    • note: in future we might be able to do for them via API from DNS hosting services
      • we could enumerate a list of supported providers (possibility for paid placement)

Out of scope:

  • no IPv6 configuration yet (we can add later)

Process:

  1. tell user to access http://freedombox.local/ (*not* https://freedombox.local/) after pluging in power and network then booting
  2. get the user to pick an IP address, subnet mask, and gateway for their fbx on their LAN
    • they will currently have a DHCP allocated address but as we can't ensure that IP will be constant/reserved (it's probably not) we want a static IP instead
  3. reconfigure fbx with nominated static IP address (192.168.0.2), netmask (255.255.255.0) and gateway (192.168.0.1)
    • don't release the DHCP address (192.168.0.123), the server will have two IP addresses during this process
  4. when static IP address settings are valid/successful (we could do a HTTP redirect dance to confirm):
    1. add firewall rule to block port 8080 access from all addresses other than current client IP address (the rest of the configuration will need to be completed from the same client)
      • this could be relaxed to blocking only gateway/router
    2. HTTP redirect over to the static IP address on port 8080 at e.g. http://192.168.0.2:8080/
  5. get the user to pick a DNS resolver service:
    • their broadband router probably proxies to their ISP DNS resolvers so we could default to that, e.g. 192.168.0.1
    • 1.1.1.1 and 1.0.0.1 as fall back
    • 8.8.8.8 also an option
    • DNS resolver is another possibility for paid placement
  6. ask the user to tell us thier domain name, e.g. 'example.com'
  7. ask user to pick a hostname at their domain, we recommend 'fbx'.
    • note that what we want is one single global unambiguous well-branded hostname for this fbx and something in the form 'fbx.example.com' is ideal
    • note that support for other domain aliases such as 'www.example.com' or 'blog.example.com' etc can be added later at the user's option
  8. tell the user to add an A record for 'fbx' for their public IP address.
    • we could offer to auto-detect public IP address
  9. configure our local Bind9 service:
    1. with DNS resolver nominated above (1.1.1.1)
    2. with an A record for 'fbx.example.com' to point to 192.168.0.2
  10. configure our Bind9 resolver on the LAN:
    1. tell user to configure DNS proxy to point to 192.168.0.2
    2. tell user to configure broadband router DHCP server with DNS server 192.168.0.1 (that's probably current default)
    3. tell user to configure non-DHCP hosts with DNS server 192.169.0.1 (that's probably current default)
    4. tell user to add /etc/hosts (or equiv) for 192.168.0.2 fbx.example.com for any LAN hosts not using our Bind9 resolver (ideally there are no such hosts)
      • if hosts file is being used instead of DNS this might affect alias configurations if those are added later on, ideal the LAN DNS will be used in preference to hosts files

User wants to register their fbx on a new domain name on their static home IP address

User wants to register their fbx on their existing domain name on their dynamic home IP address

User wants to register their fbx on a new domain name on their dynamic home IP address

Config

Email

We might use the default RDNS name as the hostname of our mail server and the hostname for our MX records.

fail2ban

If web services are behind a reverse proxy blocking IP addresses will be problematic, so maybe just don't do that? Needs some thought.

Processes

nmap discovery

Help user discover their fbx IPv4 address using an nmap command such as:

nmap -p 80 --open -sV 192.168.0.0/24

DHCP server status

Help user discover their fbx IPv4 address by reviewing the status of their DHCP server (often in the commodity internet router) and looking for 'freedombox' in the hostname or otherwise just trying allocated IP addresses to "see if they work".

Picking a DNS resolver

So we could go one of two ways when configuring our DNS resolvers:

  • fbx -> router -> internet
  • router -> fbx -> internet

The 'internet' resolvers could be one of:

  • user's ISP DNS servers
  • 1.1.1.1 and 1.0.0.1
  • 8.8.8.8
  • something else

Then we could either:

  1. make our fbx the DNS server on the LAN, which will defer to the router.
  2. make our router the DNS server on the LAN, which will defer to the fbx.

If we make the fbx the DNS server then we need to update the DHCP settings on the router to point the DNS server to our fbx.

If we make the router then DNS server then we need to update the DNS server settings on the router to point to our fbx.

Since it's six one way and half a dozen the other the way we will recommend is having the router be the primary LAN DNS server and the fbx as the DNS proxy to the internet. So that's router -> fbx -> internet. That means that we need to configure the DNS server on the router to be our fbx IP address (192.168.0.2 in our example). Because our fbx will defer to the actual DNS server we can offer choices (potentially paid placement) such as those listed as 'internet' DNS servers above (1.1.1.1).

HTTP redirect dance