@Clive_A 

Thank you for looking into my request. I understood Omada's intent to override the TTL set by the upstream. However, blindly overriding the TTL value with a higher value can lead to issues such as cache poisoning or invalid cache entries which may prevent us from going to the respective website unless we clear the cache. We can fix this by respecting the TTL set by upstream and only cache those entries that are cacheable. For example, if the upstream says the TTL is 60 secs that kind of entry need not be cached unless it is overridden by your default implementation, however, it may lead to issues I mentioned above (invalid cache).  So with min cache ttl, we can safely cache entries that our upstream deems to be valid. For example, if the upstream gave us the TTL of 300 (5 mins), we can choose to not cache anything below 5 mins thus saving ourselves from unnecessary cache or related lookup times for such short-living entries.

Alternatively, we can use max_ttl to enforce when to refresh the cache. If the upstream sets the TTL as 864000 (10 days), you can set a max_ttl of 86400 to clear the cache every day.

I would appreciate IPV6 implementation be fast-tracked.