On 02/25/2015 09:04 AM, Albert ARIBAUD wrote: > Bonjour Tomas, > > Le Wed, 25 Feb 2015 08:24:25 +0100, Tomas Hozza <[email protected]> a > écrit : > > > On 02/24/2015 05:26 PM, Jim Alles wrote: > >> You must have a very small network and very special requirements? > > It was for dhcp client testing purposes. > >> From the man pages for dhcp-range: > >> > >> Enable the DHCP server. Addresses will be given out from the range > >> <start-addr> to <end-addr> and from statically defined addresses given in > >> *dhcp-host *options. > >> If the lease time is given, then leases will be given for that length of > >> time. The lease time is in seconds, or minutes (eg 45m) or hours (eg 1h) or > >> "infinite". If not given, the default lease time is one hour. > >> > >> The minimum lease time is two minutes. > > Ahh, Thank you. I was looking for "2m" and didn't see this statement. > >> For IPv6 ranges, the lease time maybe "deprecated"; this sets the preferred > >> lifetime sent in a DHCP lease or router advertisement to zero, which causes > >> clients to use other addresses, if available, for new connections as a > >> prelude to renumbering. > >> > >> On Tue, Feb 24, 2015 at 10:11 AM, Tomas Hozza <[email protected]> wrote: > >> > >>> Hi. > >>> > >>> Even though I configure dnsmasq to git leases > >>> e.g. for 1 minute it always configures it self > >>> with 2m lease time. I was not able to get under > >>> 2m, however if the value is greater than 2m, dnsmasq > >>> configures itself correctly. > >>> > >>> using: > >>> ... > >>> dhcp-range=192.168.99.2,192.168.99.254,1m > >>> dhcp-range=fd00:dead:beef:55::100,fd00:dead:beef:55::1ff,1m > >>> ... > >>> > >>> gives: > >>> ... > >>> dnsmasq-dhcp: DHCP, IP range 192.168.99.2 -- 192.168.99.254, lease time 2m > >>> dnsmasq-dhcp: DHCPv6, IP range fd00:dead:beef:55::100 -- > >>> fd00:dead:beef:55::1ff, > >>> lease time 2m > >>> ... > >>> > >>> Why it is so? Seems like a bug IMHO. > >>> > >>> Regards, > >>> -- > >>> Tomas Hozza > >>> Software Engineer - EMEA ENG Developer Experience > >>> > >>> PGP: 1D9F3C2D > >>> Red Hat Inc. http://cz.redhat.com > > > > Anyway, my question why is this so and why is the user hard-limited? > > Is there some technical reason behind the limit? Thank you for answer. > I guess part of the answer is that the DHCP RFC 2131, while actively > not defining a minimum lease time, does specify various timings no > smaller than 60 seconds (e.g. 3.2 item 4, or 4.4.5); with a lease time > of less than 2 minutes, these various timings could not be respected. Yes, that makes sense. Thank you for pointing me to the RFC sections. > (Besides, the smaller the lease time, the bigger the bandwidth DHCP uses > for a reason (IP address change for a given host) that is not supposed > to happen just every minute. I, for one -- besides welcoming our insects > overloards -- would like to know what the use case can be for a lease > of less than 120 seconds.) Only some testing scenarios, like DHCP client software testing. Otherwise I can not think of any useful scenario. > > Thanks! > > > > Regards, > > Amicalement, > Thank you.
Regards, -- Tomas Hozza Software Engineer - EMEA ENG Developer Experience PGP: 1D9F3C2D Red Hat Inc. http://cz.redhat.com _______________________________________________ Dnsmasq-discuss mailing list [email protected] http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
