OpenWRT

[autkin]

For CityFibre.

First, create a VLAN interface.

Navigate: Network -> Interfaces.
Select tab "Devices".
Press "Add device configuration".
Select "Device type": "VLAN (802.1q)".
Select "Base device": physical interface for where the patchcord from the ONT enters.
Enter "VLAN ID" 911.
"Device name" - logical interface name, will default to e.g. `eth3.911`
Press "Save".
No other settings have to be changed at this time.


While staying on "Network -> Interfaces" page, select tab "Interfaces".
As is usual for "WAN" (public-internet-side) in OpenWRT, do "Add new interface" two times, with "Protocol" being "DHCP client", and then with "DHCPv6 client", selecting the VLAN device. I named them "olilo" and "olilo6".

IPv4 setup is relatively boring, and IPv6 is full of pitfalls and so is exciting, so I will focus on that in the explanation and screenshots.

Basically I tried different settings until LAN clients got IPv6 addresses and working pings and DNS. This happened with "RA service" and "DHCPv6 service" in "server mode" (relay mode didn't work).

 

[autkin]

more screenshots specifically about IPv6 settings

 

[autkin]

Initially I wanted to run just a NetworkManager on a Linux server, OpenWRT happens to be an odd workaround - I set up a virtual machine which owns a physical port. Some glimpses into how I did that:

incus create --vm  images:openwrt/snapshot openwrt-uplinks

incus config device add openwrt-uplinks olilo-nic nic nictype=physical name=olilo parent=eno3

# enable intel_iommu etc on host, not shown here

incus network create --type=bridge openwrt-lan

incus network attach openwrt-lan openwrt-uplinks lan

incus start --console openwrt-uplinks

# gives passwordless console

apk add luci

# initially internet works thanks to the physical host having another uplink and sharing that with the VM

# lots of configuration via web interface

This way the `openwrt-lan` bridge is managed by Incus hypervisor which is not really expecting you to use it for the physical host being a DHCP client, so for now I have done clunky static assignment of addresses and routes. I am scared to think of making this cludge "production-strength", so I hope NetworkManager will work for IPv6 eventually https://terminal.olilo.co.uk/threads/linux-networkmanager.55/