I was thinking that maybe you had a large TTL for either the SOA or the minimum TTL field, but both of those are pretty reasonable at 5 minutes and 1 minute. S

I was thinking that maybe you had a large TTL for either the SOA or the minimum TTL field, but both of those are pretty reasonable at 5 minutes and 1 minute. See this RFC, https://www.rfc-editor.org/rfc/rfc2308#section-4 https://www.rfc-editor.org/rfc/rfc2308#section-4