All routes are now installed in a custom netbird routing table.
Management and wireguard traffic is now marked with a custom fwmark.
When the mark is present the traffic is routed via the main routing table, bypassing the VPN.
When the mark is absent the traffic is routed via the netbird routing table, if:
- there's no match in the main routing table
- it would match the default route in the routing table
IPv6 traffic is blocked when a default route IPv4 route is configured to avoid leakage.
Most operating systems add a /32 route for the default gateway address to its routing table
This will allow routes to be configured into the system even when the incoming range contains the default gateway.
In case a range is a sub-range of an existing route and this range happens to contain the default gateway it attempts to create a default gateway route to prevent loop issues
