[Dnsmasq-discuss] Potential memory leak

Thu Jan 22 15:05:50 UTC 2026

 From the mailing list:

"Here's something interesting... it looks like there is a problem with 
serving DHCPv6... so after turning on radvd memory consumption started 
increasing substantially..."

How does that alter the configuration below?

Simon.

On 22.01.2026 14:05, Niten Jaiswal via Dnsmasq-discuss wrote:
> 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- 
> bounces at lists.thekelleys.org.uk> on behalf of Niten Jaiswal via Dnsmasq- 
> discuss <dnsmasq-discuss at lists.thekelleys.org.uk>
> *Date: *Tuesday, January 20, 2026 at 9:53 PM
> *To: *dnsmasq-discuss at lists.thekelleys.org.uk <dnsmasq- 
> discuss at lists.thekelleys.org.uk>
> *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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