On Fri, Jan 18, 2019 at 10:36:19AM +0100, Harald Dunkel wrote: > On 1/17/19 11:58 PM, Simon Kelley wrote:> } } http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2019q1/012822.html } } } ... VPN ... > > The delay is while dnsmasq tests the address it's about to allocate in > > case some host is already using it. It sends a ICMP echo request > > (essentially a ping) and if it gets a reply, the test fails. After a 3 > > second timeout the test succeeds and the address is allocated. If you're > > happy that there are no machines using IP addresses without leasing > > them, or that the similar test that DHCP clients do will find this, then > > you can disable the check in dnsmasq using the --no-oing config flag. > } you can disable the check in dnsmasq using the --no-ping config flag.
--no-Ping Quoting dnsmasq manual page -5, --no-ping (IPv4 only) By default, the DHCP server will attempt to ensure that an address is not in use before allocating it to a host. It does this by sending an ICMP echo request (aka "ping") to the address in question. If it gets a reply, then the address must already be in use, and another is tried. This flag disables this check. Use with caution. The 3 seconds from the subject line explained and how to avoid that delay. > Do you think dnsmasq could watch/ping its IP address range while it is > idle, caching the result? It might examine the local arp table as well: > If there is an entry with matching MAC and IP address, isn't it reasonable > to assume that the IP address is not in use somewhere else? I think that "make dnsmasq a network monitor" should be in seperate thread. Regards Geert Stappers DevOps engineer _______________________________________________ Dnsmasq-discuss mailing list Dnsmasqemail@example.com http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss