My guess is that the config file has a subtle syntax error, which means
that you're not actually configuring for infinite leases, but maybe
zero-length ones. Dnsmasq applies a floor of two minutes on leases, the
repeated renewals might indicate that is too short.

When dnsmasq starts, it logs the lease time for each DHCP address range.
Could you see what it's saying?


Cheers,

Simon.



On 31/12/2018 20:44, Marc Elbirt wrote:
> ## Expected Behaviour:
> DHCP offers should be accepted by any client
> 
> ## Actual Behaviour:
> Clients repeatedly ask for DHCP addresses, every 3 seconds, overwhelming
> pi-hole and slowing all responses (including DNS). Some client devices
> (iPhone 7) can be observed to temporarily acquire an address, and then
> drop it moments later.
> 
> ## Debug Token:
> eepv3gugqb
> 
> ## Versions:
> Dnsmasq version 2.76  Copyright (c) 2000-2016 Simon Kelley
> FTL Version v4.1.2
> Linux pi-hole 4.14.79+ #1159 Sun Nov 4 17:28:08 GMT 2018 armv6l GNU/Linux
> Raspbian GNU/Linux 9 (stretch)
> 
> ## Config notes:
> pi-hole is configured for DNS and DHCP, on subnet 192.168.2.1/24
> <http://192.168.2.1/24>. It is configured to grant infinite leases to
> any, in the range 192.168.2.129 to 192.168.2.223, and most devices
> (including the ones below) have been allocated static leases in the
> space below this range.
> 
> ## Example:
> Dec 28 08:35:18 dnsmasq-dhcp[882]: DHCPDISCOVER(wlan0) 44:61:32:xx:xx:xx 
> Dec 28 08:35:18 dnsmasq-dhcp[882]: DHCPOFFER(wlan0) 192.168.2.26
> 44:61:32:xx:xx:xx 
> Dec 28 08:35:18 dnsmasq-dhcp[882]: DHCPREQUEST(wlan0) 192.168.2.26
> 44:61:32:xx:xx:xx 
> Dec 28 08:35:18 dnsmasq-dhcp[882]: DHCPACK(wlan0) 192.168.2.26
> 44:61:32:xx:xx:xx ecobee3
> Dec 28 08:35:21 dnsmasq-dhcp[882]: DHCPREQUEST(wlan0) 192.168.2.26
> 44:61:32:xx:xx:xx 
> Dec 28 08:35:21 dnsmasq-dhcp[882]: DHCPACK(wlan0) 192.168.2.26
> 44:61:32:xx:xx:xx ecobee3
> ...
> Dec 28 08:36:23 dnsmasq-dhcp[882]: DHCPREQUEST(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx 
> Dec 28 08:36:23 dnsmasq-dhcp[882]: DHCPACK(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx PurpleAir_751
> Dec 28 08:36:26 dnsmasq-dhcp[882]: DHCPREQUEST(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx 
> Dec 28 08:36:26 dnsmasq-dhcp[882]: DHCPACK(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx PurpleAir_751
> Dec 28 08:36:28 dnsmasq-dhcp[882]: DHCPREQUEST(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx 
> Dec 28 08:36:28 dnsmasq-dhcp[882]: DHCPACK(wlan0) 192.168.2.58
> 68:c6:3a:xx:xx:xx PurpleAir_751
> 
> ## Notes:
> Testing with nmap reveals unexpected behavior, where lease time is set
> to the minimum dnsmasq time (2 mins):
> Starting Nmap 7.70 ( https://nmap.org ) at 2018-12-28 08:12 PST
> Pre-scan script results:
> | broadcast-dhcp-discover: 
> |   Response 1 of 1: 
> |     IP Offered: 192.168.2.148
> |     DHCP Message Type: DHCPOFFER
> |     Server Identifier: 192.168.2.10
> |     IP Address Lease Time: 2m00s
> |     Renewal Time Value: 1m00s
> |     Rebinding Time Value: 1m45s
> |     Subnet Mask: 255.255.255.0
> |     Broadcast Address: 192.168.2.255
> |     Domain Name Server: 192.168.2.10
> |     Domain Name: xxxxxxxx
> |_    Router: 192.168.2.1
> WARNING: No targets were specified, so 0 hosts scanned.
> Nmap done: 0 IP addresses (0 hosts up) scanned in 4.23 seconds
> 
> _______________________________________________
> Dnsmasq-discuss mailing list
> Dnsmasq-discuss@lists.thekelleys.org.uk
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> 


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