I’m running version 2.91_1.1 on opnsense version 25.7.10.  Below is my configuration:

OPNsense:~ # cat /usr/local/etc/dnsmasq.conf

# DO NOT EDIT THIS FILE -- OPNsense auto-generated file

#


rebind-localhost-ok

stop-dns-rebind


port=5353


# If you want dnsmasq to listen for DHCP and DNS requests only on

# specified interfaces (and the loopback) give the name of the

# interface (eg eth0) here.

# Repeat the line for more than one interface.

interface=ixl1




dhcp-fqdn

domain=375.jaiswal.net

# This tells dnsmasq that a domain is local and it may answer queries from /etc/hosts

# or DHCP but should never forward queries on that domain to any upstream servers.

local=/375.jaiswal.net/


dhcp-authoritative
















log-dhcp

quiet-dhcp

quiet-dhcp6

quiet-ra

quiet-tftp

# host entries flushed via dnsmasq_watcher.py [isc] and a dump of the static reservations

addn-hosts=/var/etc/dnsmasq-hosts

addn-hosts=/var/etc/dnsmasq-leases


dns-forward-max=15000

cache-size=10000

local-ttl=1


conf-dir=/usr/local/etc/dnsmasq.conf.d,*.conf


dhcp-range=tag:ixl1,X.X.X.30,X.X.X.199,86400


domain=375.jaiswal.net,X.X.X.30,X.X.X.199

dhcp-range=tag:ixl1,::1000,::2000,constructor:ixl1,64,86400


domain=X.X.X,::1000,::2000


dhcp-host=d8:0d:17:41:af:2c,X.X.X.23,TL-SG108PE

dhcp-host=68:1d:ef:18:b2:c6,X.X.X.29,camect-home-2fefa

dhcp-host=dc:f5:05:18:4e:fb,X.X.X.34,mwmdemo-4EFB

dhcp-host=1c:1d:d3:d8:23:e6,X.X.X.35,Nitens-Mac-Studio

dhcp-host=a8:51:ab:02:3f:28,X.X.X.99,Guest_Room_AppleTV

dhcp-host=00:1a:ae:00:40:4b,X.X.X.101

dhcp-host=00:1a:ae:02:5f:16,X.X.X.113

dhcp-host=88:c9:e8:bc:e9:50,X.X.X.116,Sony_A95K_FM

dhcp-host=60:81:f9:ac:66:58,X.X.X.128,Helium-Hotspot

dhcp-host=00:0c:d0:01:23:33,X.X.X.132

dhcp-host=b8:2c:a0:5b:5d:14,X.X.X.142,android-a3369b84877d627a

dhcp-host=80:a5:89:aa:42:67,X.X.X.152,mwmdemo-4267

dhcp-host=90:56:82:98:56:c2,X.X.X.201,AmanBluesound

dhcp-host=18:bb:26:e2:2f:43,X.X.X.202,RianBluesound

dhcp-host=90:56:82:40:91:49,X.X.X.203,MasterBedroom

dhcp-host=64:95:6c:0a:94:76,X.X.X.204,LG_Projector_MB

dhcp-host=38:c9:86:14:8b:ae,X.X.X.205,10ddb198e7550000

dhcp-host=20:f8:5e:4e:b5:d6,X.X.X.206,RianBedroomFan

dhcp-host=20:f8:5e:4e:ac:37,X.X.X.207,AmanBedroomFan

dhcp-host=20:f8:5e:35:e4:5c,X.X.X.208,MasterBedroomFa

dhcp-host=20:f8:5e:4e:ce:5a,X.X.X.209,FamilyRoomFan

dhcp-host=20:f8:5e:e4:44:ce,X.X.X.210,OfficeFan

dhcp-host=00:11:d9:56:96:45,X.X.X.211,TIVO-A9200019027F13F

dhcp-host=20:f8:5e:4e:ad:57,X.X.X.212,PlayRoomFan

dhcp-host=00:1b:7c:09:81:9f,X.X.X.213,sdr35-589374

dhcp-host=00:11:d9:8f:15:09,X.X.X.214,TIVO-849601190366E67

dhcp-host=14:91:82:d8:4b:70,X.X.X.221,Wemo_soffit

dhcp-host=00:1b:7c:09:81:b1,X.X.X.222,sdp55-58b1f0

dhcp-host=d4:6a:91:0e:88:d2,X.X.X.223,Wattbox

dhcp-host=ec:a9:07:10:7a:50,X.X.X.224,AppleTVvingRoom

dhcp-host=4c:ab:4f:90:c6:47,X.X.X.225,AppleTVmilyRoom

dhcp-host=c8:d0:83:ca:46:cc,X.X.X.226,MasterBAppleTV3

dhcp-host=00:11:d9:96:e8:9a,X.X.X.227,TIVO-84900119048F1A6

dhcp-host=id:00:01:00:01:2d:af:54:ce:b8:e6:0c:13:e7:1e, [::b9cc],m1_macbook_pro

dhcp-host=id:00:04:bb:36:4d:56:f5:2c:9f:11:50:7a:32:82:60:23:dd:e1, [::bbc1],pi-hole

dhcp-host=id:00:01:00:01:29:42:4e:a4:14:98:77:7b:27:6d,[::bbc2],mac- mini-server

dhcp-host=id:00:01:00:01:2e:ea:7c:b5:00:1a:1e:04:13:98,[::bbc3],aruba-master

dhcp-host=id:00:01:00:01:2e:ea:7c:b5:00:1a:1e:04:13:98,[::bbc3],aruba- conductor

dhcp-option=tag:ixl1,60,ArubaAP

dhcp-option=tag:ixl1,43,X.X.X.2

dhcp-option=tag:ixl1,66,X.X.X.10

dhcp-option=tag:ixl1,150,X.X.X.10

dhcp-option=42,X.X.X.1

dhcp-option=tag:ixl1,6,X.X.X.4

dhcp-option=tag:ixl1,option6:23,[::bbc1]


# default dns mapped to this server (0.0.0.0)

dhcp-option=6,0.0.0.0



no-ident

*From: *Dnsmasq-discuss <dnsmasq-discuss- [email protected]> on behalf of Niten Jaiswal via Dnsmasq- discuss <[email protected]>

*Date: *Tuesday, January 20, 2026 at 9:53 PM

*To: *[email protected] <dnsmasq- [email protected]>

*Subject: *[Dnsmasq-discuss] Potential memory leak

Hi!

I’m a user of opnsense and have migrated to dnsmasq for DHCPv4 and v6 services.  However, dnsmasq randomly stops functioning and I need to manually restart it to restore DHCP services to my network.  I’ve been troubleshooting the issue on the opnsense form on the following thread: https://forum.opnsense.org/index.php?topic=49552.30 <https:// forum.opnsense.org/index.php?topic=49552.30>

My basic testing points to an issue with serving DHCPv6 addresses.  When I have router advertisement set to unmanaged the memory consumption of dnsmasq was fairly stable.  When router advertisement is set to managed then dnsmasq begins consuming more and more memory..

Let me know if you need additional information.  I was asked to post to the email list by an opnsense forum moderator.

TIA
Niten

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