Regarding this topic, yesterday I updated my R4S router from OpenWrt 23.* to 25.12.
However, the guest VLAN stopped working.
Did something change significantly from 23 to 25? Should I pay attention to any specific changes, considering the topic I mentioned above? Has any syntax been changed?
Thanks!
From the 25.12 release notes...
Sysupgrade from 23.05 to 25.12 is not officially supported.
Had you gone via v24 all would have ended well.
If you have original config backup - revert to v23, restore config and upgrade gradually.
No, I misspoke. I did a clean installation, from scratch.
Enable vlans on br-lan, then tag untag on ports as you wish?
/etc/config/network:
config interface 'loopback'
option device 'lo'
option proto 'static'
list ipaddr '127.0.0.1/8'
config globals 'globals'
option dhcp_default_duid 'redacted'
option ula_prefix 'redacted'
option packet_steering '1'
config device
option name 'br-lan'
option type 'bridge'
list ports 'eth1'
config device
option name 'eth1'
option macaddr 'redacted'
config interface 'lan'
option device 'br-lan'
option proto 'static'
list ipaddr '10.0.0.1/24'
option ip6assign '60'
option multipath 'off'
config device
option name 'eth0'
option macaddr 'redacted'
config interface 'wan'
option device 'eth0'
option proto 'pppoe'
option username 'redacted'
option password 'redacted'
option ipv6 'auto'
option norelease '1'
option multipath 'off'
option peerdns '0'
config interface 'wan6'
option device 'eth0'
option proto 'dhcpv6'
option peerdns '0'
config interface 'modem'
option proto 'static'
option device 'eth0'
option ipaddr '192.168.15.2/24'
config interface 'guest'
option proto 'static'
option device 'eth1.10'
option ipaddr '10.0.10.1/24'
config interface 'iot'
option proto 'static'
option device 'eth1.20'
option ipaddr '10.0.20.1/24'
/etc/config/dhcp:
config dnsmasq
option domainneeded '1'
option boguspriv '1'
option filterwin2k '0'
option localise_queries '1'
option rebind_protection '1'
option rebind_localhost '1'
option local '/lan/'
option domain 'lan'
option expandhosts '1'
option nonegcache '0'
option cachesize '0'
option authoritative '1'
option readethers '1'
option leasefile '/tmp/dhcp.leases'
option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'
option nonwildcard '1'
option localservice '1'
option ednspacket_max '1232'
option filter_aaaa '0'
option filter_a '0'
option port '54'
option noresolv '1'
config dhcp 'lan'
option interface 'lan'
option start '10'
option limit '90'
option leasetime '12h'
option dhcpv4 'server'
option dhcpv6 'server'
option ra 'server'
list ra_flags 'managed-config'
list ra_flags 'other-config'
option ra_preference 'medium'
list dhcp_option '3,10.0.0.1'
list dhcp_option '6,10.0.0.1'
list dhcp_option '15,lan'
list dns 'fd90:2576:cb40::1'
config dhcp 'wan'
option interface 'wan'
option ignore '1'
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 dhcp 'guest'
option interface 'guest'
option start '10'
option limit '90'
option leasetime '12h'
list dhcp_option '6,94.140.14.15,94.140.15.16'
config dhcp 'iot'
option interface 'iot'
option start '10'
option limit '90'
option leasetime '12h'
list dhcp_option '6,94.140.14.15,94.140.15.16'
/etc/config/firewall:
config defaults
option syn_flood 1
option input REJECT
option output ACCEPT
option forward REJECT
# Uncomment this line to disable ipv6 rules
# option disable_ipv6 1
config zone
option name lan
list network 'lan'
option input ACCEPT
option output ACCEPT
option forward ACCEPT
config zone
option name wan
list network 'wan'
list network 'wan6'
option input REJECT
option output ACCEPT
option forward DROP
option masq 1
option mtu_fix 1
config forwarding
option src lan
option dest wan
# We need to accept udp packets on port 68,
# see https://dev.openwrt.org/ticket/4108
config rule
option name Allow-DHCP-Renew
option src wan
option proto udp
option dest_port 68
option target ACCEPT
option family ipv4
# Allow IPv4 ping
config rule
option name Allow-Ping
option src wan
option proto icmp
option icmp_type echo-request
option family ipv4
option target ACCEPT
config rule
option name Allow-IGMP
option src wan
option proto igmp
option family ipv4
option target ACCEPT
# Allow DHCPv6 replies
# see https://github.com/openwrt/openwrt/issues/5066
config rule
option name Allow-DHCPv6
option src wan
option proto udp
option dest_port 546
option family ipv6
option target ACCEPT
config rule
option name Allow-MLD
option src wan
option proto icmp
option src_ip fe80::/10
list icmp_type '130/0'
list icmp_type '131/0'
list icmp_type '132/0'
list icmp_type '143/0'
option family ipv6
option target ACCEPT
# Allow essential incoming IPv6 ICMP traffic
config rule
option name Allow-ICMPv6-Input
option src wan
option proto icmp
list icmp_type echo-request
list icmp_type echo-reply
list icmp_type destination-unreachable
list icmp_type packet-too-big
list icmp_type time-exceeded
list icmp_type bad-header
list icmp_type unknown-header-type
list icmp_type router-solicitation
list icmp_type neighbour-solicitation
list icmp_type router-advertisement
list icmp_type neighbour-advertisement
option limit 1000/sec
option family ipv6
option target ACCEPT
# Allow essential forwarded IPv6 ICMP traffic
config rule
option name Allow-ICMPv6-Forward
option src wan
option dest *
option proto icmp
list icmp_type echo-request
list icmp_type echo-reply
list icmp_type destination-unreachable
list icmp_type packet-too-big
list icmp_type time-exceeded
list icmp_type bad-header
list icmp_type unknown-header-type
option limit 1000/sec
option family ipv6
option target ACCEPT
config rule
option name Allow-IPSec-ESP
option src wan
option dest lan
option proto esp
option target ACCEPT
config rule
option name Allow-ISAKMP
option src wan
option dest lan
option dest_port 500
option proto udp
option target ACCEPT
config zone
option name 'guest'
option input 'REJECT'
option output 'ACCEPT'
option forward 'REJECT'
list network 'guest'
config forwarding
option src 'guest'
option dest 'wan'
config rule
option name 'Guest-DHCP'
list proto 'udp'
option src 'guest'
option dest_port '67-68'
option target 'ACCEPT'
config zone
option name 'iot'
option input 'REJECT'
option output 'ACCEPT'
option forward 'REJECT'
list network 'iot'
config forwarding
option src 'iot'
option dest 'wan'
config rule
option name 'IoT-DHCP'
list proto 'udp'
option src 'iot'
option dest_port '67-68'
option target 'ACCEPT'
/etc/config/network:
config interface 'loopback'
option device 'lo'
option proto 'static'
list ipaddr '127.0.0.1/8'
config globals 'globals'
option dhcp_default_duid 'redacted'
option ula_prefix 'redacted'
option packet_steering '1'
config device
option name 'br-lan'
option type 'bridge'
list ports 'lan'
config interface 'lan'
option device 'br-lan.1'
option proto 'static'
list ipaddr '10.0.0.3/24'
option ip6assign '60'
option gateway '10.0.0.1'
list dns '10.0.0.1'
config bridge-vlan
option device 'br-lan'
option vlan '1'
list ports 'lan:u*'
config interface 'guest'
option proto 'none'
option device 'br-lan.10'
config bridge-vlan
option device 'br-lan'
option vlan '10'
list ports 'lan:t'
config interface 'iot'
option proto 'none'
option device 'br-lan.20'
config bridge-vlan
option device 'br-lan'
option vlan '20'
list ports 'lan:t'
/etc/config/wireless:
config wifi-device 'radio0'
option type 'mac80211'
option path '1e140000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
option band '2g'
option channel '1'
option htmode 'HT20'
option country 'BR'
option cell_density '0'
config wifi-iface 'wifinet1'
option device 'radio0'
option mode 'ap'
option ssid 'IoT'
option encryption 'psk2'
option key 'redacted'
option network 'iot'
list maclist 'redacted'
option macfilter 'allow'
What am I doing wrong? 
Your config looks mostly fine.
I suspect that you need to issue dhcp option 3 to set the gateway. This is because of the changes you've made to dnsmasq (this happens with things like AdGuard, DoH/DoT, etc.).
Add this line to the DHCP servers for iot and guest (use the correct gateway for each, of course):
(the above is quoted from your lan DHCP server... modify accordingly for the other two networks).
Then reboot and test again.
config dhcp 'guest'
option interface 'guest'
option start '10'
option limit '90'
option leasetime '12h'
list dhcp_option '3,10.0.10.1'
list dhcp_option '6,94.140.14.15,94.140.15.16'
config dhcp 'iot'
option interface 'iot'
option start '10'
option limit '90'
option leasetime '12h'
list dhcp_option '3,10.0.20.1'
list dhcp_option '6,94.140.14.15,94.140.15.16'
Like this?
Rebooted… but my IoT device still can’t obtain an IP address.
For reference, here are some AP logs:
root@U6Lite:~# logread -f | grep hostapd
Mon Mar 9 15:41:20 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: deauthenticated due to local deauth request
Mon Mar 9 15:41:20 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: authenticated
Mon Mar 9 15:41:20 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: associated (aid 1)
Mon Mar 9 15:41:30 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: deauthenticated due to local deauth request
Mon Mar 9 15:41:30 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: authenticated
Mon Mar 9 15:41:30 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: associated (aid 1)
Mon Mar 9 15:41:39 2026 daemon.info hostapd: phy0-ap0: STA redacted-macaddress IEEE 802.11: deauthenticated due to local deauth request
option htmode 'HT20'
I just removed this line from /etc/config/wireless… and it works again.
Was this expected/documented?
You are supposed to use luci to configure wifi.....