On Thu, Apr 16, 2020 at 11:40:59PM -0400, Rich Felker wrote: > TC bit is for truncation, and means that the complete response would > have been larger than 512 bytes and was truncated to whatever number > of whole RRs fit in 512 bytes.
Actually whole RRsets. Nameservers must not truncate in the middle of an RRset. Stub resolvers need to perform TCP retries on TC=1. -- Viktor.