[BUG] GL-E5800 Mudi 7 — LAN DHCP DNS setting is lost after reboot
Summary
On a GL.iNet Mudi 7 (GL-E5800), a custom DNS server entered in the LAN DHCP settings is saved and active before reboot. After reboot, DHCP option 6 is absent from the persistent configuration and the DNS field in the GL.iNet interface is empty.
The user reports that the behavior is reproducible. This investigation captured one complete before-and-after reboot transition.
Environment
| Item | Value |
|---|---|
| Device | GL.iNet Mudi 7 / GL-E5800 |
| GL.iNet firmware | 4.8.5 |
| OpenWrt | 23.05.4 r24012-d8dd03c46f |
| Kernel | 5.15.170-perf |
| Internet connection | Cellular |
| VPN | WireGuard |
| LAN | 10.100.1.0/24 |
| Configured DHCP DNS server | 10.10.70.100 |
The DNS server is on a private network reachable through WireGuard. This is the setup in which the problem was observed; it has not been established as the cause.
Steps to reproduce
-
Connect the router to the Internet through its cellular connection.
-
Enable the WireGuard client that provides access to
10.10.70.100. -
In the GL.iNet LAN DHCP advanced settings, enter
10.10.70.100as the first DNS server and apply the configuration. -
Confirm that
uci show dhcp.lancontains:
dhcp.lan.dhcp_option='3,10.100.1.1' '6,10.10.70.100'
-
Confirm that
uci changes dhcpreturns no output. -
Reboot the router normally.
-
Inspect the LAN DHCP DNS field and run
uci show dhcp.lananduci changes dhcpafter boot.
Expected result
The committed LAN DHCP DNS server remains configured after reboot.
Actual result
After reboot, DHCP option 6 is absent and the DNS field in the GL.iNet interface is empty. uci changes dhcp returns no output, showing that the post-reboot state is persistent rather than an uncommitted change.
The GL.iNet LAN RPC returns an empty DNS list, and the generated dnsmasq configurations do not contain option 6.
Captured before-and-after state
Before reboot:
dhcp.lan.dhcp_option='3,10.100.1.1' '6,10.10.70.100'
GL.iNet LAN RPC:
{"interface":"lan","dns":["10.10.70.100"]}
Generated dnsmasq configuration:
dhcp-option=lan,6,10.10.70.100
After reboot:
dhcp.lan.dhcp_option='3,10.100.1.1'
dhcp.lan.dhcp_option_force='26,1472'
GL.iNet LAN RPC:
{"interface":"lan","dns":[]}
Generated dnsmasq configurations no longer contain option 6.
Relevant configuration diff:
config dhcp 'lan'
list dhcp_option '3,10.100.1.1'
- list dhcp_option '6,10.10.70.100'
+ list dhcp_option_force '26,1472'
The persistent DHCP configuration changed during boot. The available evidence does not identify the exact process responsible.