On 25/08/2019 23:55, Robert Elz wrote:
detached addrs are no different really than addrs that don't exist (at least for a time).
So address persistence is a thing. for dhcpcd, when the carrier drops all addresses and config are removed until it can validate an address on a new link - to ensure we don't use an address we're not supposed to.
On NetBSD it's different - because the kernel handles DaD for IPv4 and IPv6 addresses AND denies sending from them until validated dhcpcd allows them to persist. This has the added benefit of persisting things such as ssh if the subnet changes from wired to wireless and back again.
Now, if the link drops, the address will become detached so the new dhcpcd will then drop the default route. This may kill traffic which would be bad if the address comes back in a reasonable time. Hence my thought to just restrict lack of a default route to duplicated addresses.
But I've not entirely thought this through yet, hence the current state of just using useable addresses.
Roy