Serve-expired not working in combination with send-client-subnet ?

Unbound
1

Hello,

I have an unbound.conf [1] that has both the 'serve-expired'-options and 'send-client-subnet'-options enabled.

And in that case the serving stale data feature does no longer work.

Only after I remove the 'send-client-subnet'-lines, the serving stale data functionality is working again.

Is that a bug or a feature?

2

Hi Marco,

Two things:
- The 'serve-expired-client-timeout:' has no support for the subnet
   module. That means that when the client timeout is reached, Unbound
   will try to find an (expired) answer in the *global* cache and reply
   to the client(s).

- The subnet module has no support for expired answers.

(I believe we need startup warnings and cleaner documentation for those)

So if your answers are stored in the ECS cache, serve-expired logic will not be able to find them.
If your answers are stored in the global cache (because based on your configuration the upstream has no support for ECS) then serve-expired logic will be able to find them after the serve-expired-client-timeout.

Is that what you experience?

Best regards,
-- Yorgos

3

Hi Yorgos,