-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 26/08/15 07:57, Harald Dunkel wrote: > Hi Simon, > > On 08/25/15 23:18, Simon Kelley wrote: >> >> Dnsmasq does the check which the standards require, which is to >> send an ICMP ping (echo request) to the address it's about to >> allocate. The fact that the client doesn't respond would seem to >> indicate that the clients are NOT using IP addresses after the >> lease has expired. >> > > I think the ping test would be pretty helpful. > > The IPv4 address range is set to 10.10.0.0/16. Lease time is 1h. > There are less than 200 DHCP clients in my net. Even without ping > test it should be easy to avoid a conflict. > >> My guess is that what's happening here is that the ARP-table >> entry on the server persisting after the lease expires. When the >> IP address is given to a new client, dnsmasq updates the ARP >> table, and those are just warnings that the ARP table for >> 10.10.123.204 is being overwritten. >> > > That would mean its a one-time event within the lease time. Looking > at the log file it seems to me that both clients keep on using the > same IP address for days and that the ARP entry for the conflicting > IP address is overwritten again and again within a few minutes. > > BTW, I found both devices of my test case: Its an AppleTV 2 and an > old Airport. I gave the Airport a static IP address 10.10.255.254. > It started using it, but the ARP warnings about 10.10.123.204 and > the Airport's MAC address continued to popup in the logfile. After > a power cycle of the Airport the warnings are gone. >
That's pretty strong evidence of mis-behavior, but I don't understand how neither dnsmasq (using ICMP ping) or the DHCP clients (using ARP) are noticing these hosts still camping on the IP addresses. Cheers, Simon. > > Hope this helps. Regards Harri > > > > _______________________________________________ Dnsmasq-discuss > mailing list Dnsmasq-discuss@lists.thekelleys.org.uk > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBCAAGBQJV3i7PAAoJEBXN2mrhkTWiLBEP/As472fRF+foWqKjpK/L4H+P fbR6nmdGWojkjHdOE3LFttfk8azuftxrFZpFzLD2LSO3mnGK0GkcPaOWS5d7Ar4r xQOkeFsoLXAw7Mk/7mWPd+TJ7ItO5CgSSNE73GlnOlhfWLVaQnXJJV+XrXx3n3sf 9Y+6G9JPT6R+scoZnDp1DdciFd/mWkgg1AYybFKyg7Y6dGWgTTctE+cI4MR82QiW JBe4Grj9DwTsz+LD8cSo7q9xLT4J3IE991QujT/+Ch/IQwtjtxEtkH9El16uNYdH 2GugIlgn+C//JmiLXUO9wFveIbzt6PAsu9avRnONW8ni+mXXKe+aILetGUCpzcFz bfqnZkPLibq2v162LhSUncYMB7QnYtbScSOMjxwgR9vzk1oY8MKvyHaerZxlDDtM VC9w6kQ9CfrtbO9zWMEzA6KyXqC7zQ0CN9n6+UcIuhy1qZYQykSWVvm+r+uvtiyq nZIntlmqMpMAhQb2i1u6M82PJibZrHUMhjNvUnpSBid+ZlvrYndot6gcvjX5xMsV UCGWjw8/IRVdLzWwYFgB301PHVdzYDxTL6Aypp2d52S2mHqWOdZTjINh7bR0lAre ZxOCqWjOgxyPnBbBmyfFqp597Rp+gafwWex2NwxphqjosrxNVT71WPyA9yKmF50Y S1u070y0r3Y/El0JFt83 =BPm4 -----END PGP SIGNATURE----- _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
