Hi Thomas, On 07.08.20 22:18, Thomas wrote: > I have the requirement to re-sign my zones exactly every 24 hours. I'm > not sure how to achieve this, because I'm not clear about the > correlation of the following parameters: > > zsk-lifetime > propagation-delay > rrsig-lifetime > rrsig-refresh > rrsig-pre-refresh > > > Can anybody give a hint what values I need to have an exact re-signing > period of 24 hours?
You can configure knot to renew your signatures every 24 hours: rrsig-lifetime defaults to 14 days (validity period). Let's keep that. rrsig-refresh defaults to 7 days and is coupled to rrsig-lifetime. Set it to 13 days so that signatures are re-newed 13 days before they expire which is your required 24 hours. So, the required setting is only: rrsig-refresh: 13d Note, we ignored that the signatures are created with an inception time of 90 minutes in the past. This means, knot will resign your zone every 24h - 90min interval. If this is a problem for you, you need to either decrease rrsig-lifetime by 90min or increase rrsig-refresh by 90min. Even then, it will likely not happen exactly every 24h as rrsig-pre-refresh (defaults to 60min) allows knot to refresh it up to 60 minutes before. This is to avoid re-signing huge numbers of signatures all at the same time. In my opinion, I would just use the "rrsig-refresh" option as shown above. I once made a picture how this parameters align together: https://switchsecurityblog.files.wordpress.com/2014/11/blog-time-in-dnssec.png Daniel -- https://lists.nic.cz/mailman/listinfo/knot-dns-users
