Am Mon, 10 Apr 2017 12:46:02 +0200 schrieb Lennart Poettering <[email protected]>:
> On Mon, 10.04.17 12:41, Kai Krakow ([email protected]) wrote: > > > > Queries and responses in LLMNR are supposed to be delayed by a > > > random time up to 100ms according to the RFC. See: > > > > > > https://tools.ietf.org/html/rfc4795 section 2.7, and section 7. > > > > > > If you add up the delay for the query and the response you'll get > > > a delay up to 200ms for a full transaction. > > > > Well it seems a bit more complicated: > > > > The random delays are a combined value of jitter and timeout. And it > > depends on whether you're currently the sender or responder: > > Responders have shorter timeouts (only jitter), according to > > section 2.7. > > > > It also says SHOULD wait (so it is a good idea), and it says the > > jitter MAY be ignored if the responder knows the name is unique. > > Only the sender MUST wait for timeout+jitter. > > > > This is where the 200ms come from, but it may even be 1000+100ms if > > you are connected to none-IEEE 802.* media, e.g. VPN or PPP > > interfaces and LLMNR is configured to listen on these, as far as I > > understand section 7. > > > > According to RFC2119, the terminology SHOULD suggests that systemd > > could maybe make this configurable? Maybe taking the proper > > warnings for this configuration into account for administrators... > > Still you would see delays of at least 100ms then because the > > sender MUST wait. > > I am not a fan of configuration options in zeroconfey technology like > this one I must say. I mean "zeroconf" is about "zero configuration", > hence making it configurable creates kind of a tautology... As I pointed out it wouldn't have a big effect anyways, so probably you're perfectly right. Is there a way to know the delays used, i.e. if it 1000 or 100ms? -- Regards, Kai Replies to list-only preferred. _______________________________________________ systemd-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/systemd-devel
