Hello,
finally I had some time to check why 25.12.0 crashes on my Edgerouter.
The problem is this, simple and plain: when I enable dhcp IP reservation dnsmasq always crashes at reboot.
No way to solve: I tried changing via Luci, via editing text file.
Let’s take a look at the config files.
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button (red circle; this works best in the 'Markdown' composer view in the blue oval):
Remember to redact passwords, VPN keys, MAC addresses and any public IP addresses you may have:
ubus call system board
cat /etc/config/network
cat /etc/config/dhcp
cat /etc/config/firewall
BusyBox v1.37.0 (2026-03-17 01:31:57 UTC) built-in shell (ash)
_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
-----------------------------------------------------
OpenWrt 25.12.1, r32768-b21cfa8f8c Dave's Guitar
-----------------------------------------------------
OpenWrt recently switched to the "apk" package manager!
OPKG Command APK Equivalent Description
------------------------------------------------------------------
opkg install <pkg> apk add <pkg> Install a package
opkg remove <pkg> apk del <pkg> Remove a package
opkg upgrade apk upgrade Upgrade all packages
opkg files <pkg> apk info -L <pkg> List package contents
opkg list-installed apk info List installed packages
opkg update apk update Update package lists
opkg search <pkg> apk search <pkg> Search for packages
------------------------------------------------------------------
For more information visit:
https://openwrt.org/docs/guide-user/additional-software/opkg-to-apk-cheatsheet
root@EdgeRouter_X:~# ubus call system board
{
"kernel": "6.12.74",
"hostname": "EdgeRouter_X",
"system": "MediaTek MT7621 ver:1 eco:3",
"model": "Ubiquiti EdgeRouter X",
"board_name": "ubnt,edgerouter-x",
"rootfs_type": "squashfs",
"release": {
"distribution": "OpenWrt",
"version": "25.12.1",
"firmware_url": "https://downloads.openwrt.org/",
"revision": "r32768-b21cfa8f8c",
"target": "ramips/mt7621",
"description": "OpenWrt 25.12.1 r32768-b21cfa8f8c",
"builddate": "1773711117"
}
}
root@EdgeRouter_X:~# cat /etc/config/network
config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix '*****::/48'
option packet_steering '2'
option dhcp_default_duid '****ccc'
config device
option name 'br-lan'
option type 'bridge'
list ports 'eth1'
list ports 'eth2'
list ports 'eth3'
list ports 'eth4'
config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.0.1'
option netmask '255.255.255.0'
list dns '192.168.0.86'
list dns '192.168.0.246'
config interface 'wan'
option device 'eth0'
option proto 'dhcp'
config interface 'wan6'
option device 'eth0'
option proto 'dhcpv6'
option disabled '1'
option reqaddress 'try'
option reqprefix 'auto'
option norelease '1'
root@EdgeRouter_X:~# cat /etc/config/dhcp
config dnsmasq
option domainneeded '1'
option localise_queries '1'
option rebind_protection '1'
option rebind_localhost '1'
option local '/lan/'
option domain 'lan'
option expandhosts '1'
option cachesize '1000'
option authoritative '1'
option readethers '1'
option leasefile '/tmp/dhcp.leases'
option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'
option localservice '1'
option ednspacket_max '1232'
config dhcp 'lan'
option interface 'lan'
option start '2'
option limit '200'
option leasetime '12h'
option dhcpv4 'server'
config dhcp 'wan'
option interface 'wan'
option start '100'
option limit '150'
option leasetime '12h'
config odhcpd 'odhcpd'
option maindhcp '0'
option leasefile '/tmp/odhcpd.leases'
option leasetrigger '/usr/sbin/odhcpd-update'
option loglevel '4'
option piodir '/tmp/odhcpd-piodir'
option hostsdir '/tmp/hosts'
config host
option name 'PC'
option ip '192.168.0.44'
list mac '***'
root@EdgeRouter_X:~# cat /etc/config/firewall
Here is my output from the above commands.
I did remove some static leases (config host)
Comparing between the 24.10.6 output, as far as i can see there is no difference
Out of curiosity, is there a particular need to have a DHCP scope enabled and active on your router’s WAN interface? /etc/config/network defines WAN as a DHCP client, so it seems unlikely that the same interface would also need to act as a DHCP server.
That is the default setting of my modem.
Even so, we’re trying to troubleshoot your EdgeRouter, not your modem.
I’ve got an EdgeRouter X buried in a box somewhere here. I’ve never put OpenWRT on it. This may be an opportunity to see if I can do so and replicate your problem… assuming I can find the thing in the first place. It may take me a while.
In the meantime, as an experiment, try enabling the “ignore” option for the WAN interface, either via Luci or by editing /etc/config/dhcp directly.
As another experiment, consider upgrading to 25.12.1; it’s possible that there may genuinely be a bug in the software which may have been fixed in the newer version.
Thanks for your help, I have set the ignore interface checkmark.
With the 25.12.1 version no internet, with the 24.10.6 version the internet is fine.
Strange thing is on an Android tablet i have internet with the 25.12.1 version.
But the laptop, tv, iPhone is disconnected from the internet with the 25.12.1 version.
It’s quite likely the static leases are incorrectly defined. dnsmasq would complain on startup about errors. Is there anything in the syslog from when it fails? logread -e dnsmasq
Share the /var/etc/dnsmasq.conf* file while it’s crashing.
Found the cause of the problem.
Upgrading from 24.10.x to 25.12.x the mac address static leases where converted from xx:xx to xx-xx ( : was translated to - ).
This obviously caused a failure of dnsmasq.
root@EdgeRouter_X:~# logread -e dnsmasq
Sat Mar 21 13:06:37 2026 user.notice dnsmasq: DNS rebinding protection is active, will discard upstream RFC1918 responses!
Sat Mar 21 13:06:37 2026 user.notice dnsmasq: Allowing 127.0.0.0/8 responses
Sat Mar 21 13:06:37 2026 user.notice dnsmasq: Allowing RFC1918 responses for domain 192.168.0.86
Sat Mar 21 13:06:37 2026 user.notice dnsmasq: Allowing RFC1918 responses for domain 192.168.0.246
Sat Mar 21 13:06:37 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:37 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:42 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:42 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:47 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:47 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:48 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:48 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:50 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:50 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:55 2026 daemon.crit dnsmasq[1]: DHCP host has multiple names at line 31 of /var/etc/dnsmasq.conf.cfg01411c
Sat Mar 21 13:06:55 2026 daemon.crit dnsmasq[1]: FAILED to start up
Sat Mar 21 13:06:56 2026 daemon.info procd: Instance dnsmasq::cfg01411c s in a crash loop 6 crashes, 0 seconds since last crash
root@EdgeRouter_X:~# logread -e dnsmasq
So to solve the problem the MAC address must be converted to AB-00-AB-00-AB-00 in the dnsmasq.conf?
Run this to see the line numbers.
grep -n . /var/etc/dnsmasq.conf.cfg01411c
30:dhcp-host=XX:XX:XX:XX:01:XX,192.168.0.246,PiHole,7d
31:dhcp-host=XX-XX-XX-XX-01-XX,192.168.0.123,Synology.NAS
Line 31 is the line with the error, and that is the only line with the minus “-” in the MAC address
Yes, replace the dashes with colons in the dhcp config. LuCI allows it, but dnsmasq doesn’t seem to like it.
Problem solved, thank you all!!
It’s probably worth checking with @systemcrash on whether LuCI should accept a dashed MAC address. This commit seemed to allow the dash separator:
Edit: I don’t think it’s the dashes explicitly. I don’t read C well enough, but dnsmasq parses MACs with dashes in its parse_hex() function.
The error comes from dnsmasq thinking there are multiple hostnames for this dhcp-host entry (line 4206):
Edit: I give up on links to the dnsmasq git web. Always broken.
Depends where the input is, since MACs are used in various areas. That commit allowed both : and - separators. Likely inspired by firewall handling which also accepts both.
The pre-selectable values in static hosts all contain : which seems preferred. Was the hyphen separated MAC a problem?
I think there’s more going on here than the hyphens. I can add a hyphened MAC just fine and dnsmasq doesn’t complain. More context is needed from those seeing the issue.
Hi, tried the - separator also on my gl.inet MT2500 with 25.12.1 installed: even there dnsmasq fails.
So it seems to me that on 25.12.x branch only : separator is allowed.