For a long time, ntpq and its mostly text-based mode 6 (control) protocol have been preferred over ntpdc and its mode 7 (private request) protocol for runtime queries and configuration. There has been a goal of deprecating ntpdc, previously held back by numerous capabilities exposed by ntpdc with no ntpq equivalent. I have been adding commands to ntpq to cover these cases, and I believe I've covered them all, though I've not compared command-by-command recently.
As I've said previously, the binary mode 7 protocol involves a lot of hand-rolled structure layout and byte-swapping code in both ntpd and ntpdc which is hard to get right. As ntpd grows and changes, the changes are difficult to expose via ntpdc while maintaining forward and backward compatibility between ntpdc and ntpd. In contrast, ntpq's text-based, label=value approach involves more code reuse and allows compatible changes without extra work in most cases. Mode 7 has always been defined as vendor/implementation-specific while mode 6 is described in RFC 1305 and intended to be open to interop with other implementations. There is an early draft of an updated mode 6 description that likely will join the other NTPv4 RFCs eventually. [1] For these reasons, ntpd 4.2.7p230 by default disables processing of ntpdc queries, reducing ntpd's attack surface and functionally deprecating ntpdc. If you are in the habit of using ntpdc for certain operations, please try the ntpq equivalent. If there's no equivalent, please open a bug report at http://bugs.ntp.org./ Thanks, Dave Hart [1] http://tools.ietf.org/html/draft-odonoghue-ntpv4-control-01 _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
