[SOLVED] IoT VLAN configuration

tneck · November 11, 2025, 7:50pm

I'm trying to set up my network with 3 VLANs on my Flint 2 router:

IoT VLAN: isolated from rest of the regular network. wireless only
HA VLAN: HomeAssistant runs here, it can access the other two VLANs. set to port 5 on my router
LAN: everything else

I followed a bunch of guides, but I can't get DHCP working on HA and IoT. In both cases IPv6 addresses are assigned, but not IPv4.

I'd appreciate any help you folks could offer. Current configuration follows.

Wireless:

config wifi-device 'radio0'
	option type 'mac80211'
	option path 'platform/soc/18000000.wifi'
	option band '2g'
	option channel '1'
	option htmode 'HE20'
	option cell_density '0'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'IoT'
	option mode 'ap'
	option ssid 'Charlie'
	option encryption 'psk2'
	option key 'Imapassword1234f'
	option isolate '1'

config wifi-device 'radio1'
	option type 'mac80211'
	option path 'platform/soc/18000000.wifi+1'
	option band '5g'
	option channel '36'
	option htmode 'HE80'
	option disabled '1'

config wifi-iface 'default_radio1'
	option device 'radio1'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

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 'fd7b:9a13:5372::/48'
	option packet_steering '1'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

config interface 'lan'
	option device 'br-lan.1'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config interface 'wan'
	option device 'eth1'
	option proto 'dhcp'

config interface 'wan6'
	option device 'eth1'
	option proto 'dhcpv6'

config bridge-vlan
	option device 'br-lan'
	option vlan '1'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

config bridge-vlan
	option device 'br-lan'
	option vlan '3'

config bridge-vlan
	option device 'br-lan'
	option vlan '10'

config interface 'HA'
	option proto 'static'
	option device 'lan5'
	option ipaddr '192.168.3.1'
	option netmask '255.255.255.0'

config interface 'IoT'
	option proto 'static'
	option device 'br-iot.10'
	option ipaddr '192.168.10.1'
	option netmask '255.255.255.0'

config device
	option type 'bridge'
	option name 'br-iot'
	option bridge_empty '1'
	list ports 'br-lan.3'

config bridge-vlan
	option device 'br-iot'
	option vlan '10'
	list ports 'br-lan.3'

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 '1000'
	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'

config dhcp 'lan'
	option interface 'lan'
	option start '100'
	option limit '150'
	option leasetime '12h'
	option dhcpv4 'server'
	option dhcpv6 'server'
	option ra 'server'
	list ra_flags 'managed-config'
	list ra_flags 'other-config'

config dhcp 'wan'
	option interface 'wan'
	option ignore '1'

config odhcpd 'odhcpd'
	option maindhcp '0'
	option leasefile '/tmp/hosts/odhcpd'
	option leasetrigger '/usr/sbin/odhcpd-update'
	option loglevel '4'
	option piofolder '/tmp/odhcpd-piofolder'

config dhcp 'HA'
	option interface 'HA'
	option start '100'
	option limit '150'
	option leasetime '12h'

config dhcp 'IoT'
	option interface 'IoT'
	option start '100'
	option limit '150'
	option leasetime '12h'

psherman · November 11, 2025, 9:15pm

You've got a few issues in your network config file. You didn't share your firewall file -- that may be critical as well. Please show us /etc/config/firewall.

Meanwhile...

Since IoT is wireless only, we don't need anything more than an empty bridge.
Therefore, remove the ports line in br-iot (it's both unnecessary and incorrect to nest bridges like this; but also you don't need ethernet):

Delete this which is entirely wrong:

And now change the device to simply br-iot.

Now, clean up the rest... delete these since they're not being used (and were incorrect for the way that you used them anyway):

We'll leave the bridge-vlan in place in case you ever need to adjust the VLAN port assignments.
But, I recommend explicitly marking the ports as untagged + PVID for VLAN 1:

config bridge-vlan
	option device 'br-lan'
	option vlan '1'
	list ports 'lan1:u*'
	list ports 'lan2:u*'
	list ports 'lan3:u*'
	list ports 'lan4:u*'

Your DHCP file looks fine, but your firewall may have issues.

tneck · November 11, 2025, 9:48pm

Thanks so much. Below are my firewall and updated network.

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 'fd7b:9a13:5372::/48'
	option packet_steering '1'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

config interface 'lan'
	option device 'br-lan.1'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config interface 'wan'
	option device 'eth1'
	option proto 'dhcp'

config interface 'wan6'
	option device 'eth1'
	option proto 'dhcpv6'

config bridge-vlan
	option device 'br-lan'
	option vlan '1'
	list ports 'lan1:u*'
	list ports 'lan2:u*'
	list ports 'lan3:u*'
	list ports 'lan4:u*'

config interface 'HA'
	option proto 'static'
	option device 'lan5'
	option ipaddr '192.168.3.1'
	option netmask '255.255.255.0'

config interface 'IoT'
	option proto 'static'
	option device 'br-iot'
	option ipaddr '192.168.10.1'
	option netmask '255.255.255.0'

config device
	option type 'bridge'
	option name 'br-iot'
	option bridge_empty '1'

config bridge-vlan
	option device 'br-iot'
	option vlan '10'

Firewall:

config defaults
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option synflood_protect '1'

config zone
	option name 'lan'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'ACCEPT'
	list network 'lan'

config zone
	option name 'wan'
	list network 'wan'
	list network 'wan6'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option masq '1'
	option mtu_fix '1'

config forwarding
	option src 'lan'
	option dest 'wan'

config rule
	option name 'Allow-DHCP-Renew'
	option src 'wan'
	option proto 'udp'
	option dest_port '68'
	option target 'ACCEPT'
	option family 'ipv4'

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'

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'

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'

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 'ha_zone'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	list network 'HA'

config zone
	option name 'iot_zone'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	list network 'IoT'

config forwarding
	option src 'iot_zone'
	option dest 'ha_zone'

config forwarding
	option src 'iot_zone'
	option dest 'wan'

config rule
	option src 'ha_zone'
	option dest 'iot_zone'
	option name 'HA_to_IoT'
	option target 'ACCEPT'

config rule
	option src 'lan'
	option dest 'ha_zone'
	option name 'LAN_to_HA'
	option target 'ACCEPT'

config rule
	option src 'iot_zone'
	option dest 'lan'
	option name 'IoT_DHCP'
	list proto 'udp'
	option src_port '68'
	option dest_port '67'
	option target 'ACCEPT'

config rule
	option src 'iot_zone'
	option dest 'lan'
	option name 'IoT_DNS'
	option dest_port '53'
	option target 'ACCEPT'

config rule
	option src 'ha_zone'
	option dest 'lan'
	option name 'HA_to_LAN'
	option target 'ACCEPT'

config forwarding
	option src 'lan'
	option dest 'ha_zone'

config forwarding
	option src 'ha_zone'
	option dest 'lan'

psherman · November 11, 2025, 10:07pm

Remove this:

Delete these:

tneck:

config rule
	option src 'ha_zone'
	option dest 'iot_zone'
	option name 'HA_to_IoT'
	option target 'ACCEPT'

config rule
	option src 'lan'
	option dest 'ha_zone'
	option name 'LAN_to_HA'
	option target 'ACCEPT'

Remove the destination zone (lan), and the source port:

You need a similar rule covering the ha zone which I don’t see in your current config.

tneck · November 11, 2025, 11:41pm

I'm a bit closer now, but my IoT network still can't assign IPs. DHCP works over the HA network though.

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 'fd7b:9a13:5372::/48'
	option packet_steering '1'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'

config interface 'lan'
	option device 'br-lan.1'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'

config interface 'wan'
	option device 'eth1'
	option proto 'dhcp'

config interface 'wan6'
	option device 'eth1'
	option proto 'dhcpv6'

config bridge-vlan
	option device 'br-lan'
	option vlan '1'
	list ports 'lan1:u*'
	list ports 'lan2:u*'
	list ports 'lan3:u*'
	list ports 'lan4:u*'

config interface 'HA'
	option proto 'static'
	option device 'lan5'
	option ipaddr '192.168.3.1'
	option netmask '255.255.255.0'

config interface 'IoT'
	option proto 'static'
	option device 'br-iot'
	option ipaddr '192.168.10.1'
	option netmask '255.255.255.0'

config device
	option type 'bridge'
	option name 'br-iot'
	option bridge_empty '1'

Firewall:

	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option synflood_protect '1'

config zone
	option name 'lan'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'ACCEPT'
	list network 'lan'

config zone
	option name 'wan'
	list network 'wan'
	list network 'wan6'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option masq '1'
	option mtu_fix '1'

config forwarding
	option src 'lan'
	option dest 'wan'

config rule
	option name 'Allow-DHCP-Renew'
	option src 'wan'
	option proto 'udp'
	option dest_port '68'
	option target 'ACCEPT'
	option family 'ipv4'

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'

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'

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'

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 'ha_zone'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	list network 'HA'

config zone
	option name 'iot_zone'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	list network 'IoT'

config forwarding
	option src 'iot_zone'
	option dest 'ha_zone'

config forwarding
	option src 'iot_zone'
	option dest 'wan'

config rule
	option src 'iot_zone'
	option name 'IoT_DHCP_DNS'
	option target 'ACCEPT'
	list proto 'tcp'
	list proto 'udp'
	option dest_port '67 53'

config rule
	option src 'ha_zone'
	option name 'HA_to_LAN'
	option target 'ACCEPT'

config forwarding
	option src 'lan'
	option dest 'ha_zone'

config forwarding
	option src 'ha_zone'
	option dest 'lan'

psherman · November 11, 2025, 11:45pm

If you're creating a combined rule for dhcp and dns, simply remove the protocol lines. When not specified, it is TCP + UDP:

Delete this:

Then restart and test again.

tneck · November 12, 2025, 12:00am

Fantastic! That fixed it all. Thanks very much for the help.

psherman · November 12, 2025, 12:04am

You're welcome!

If your problem is solved, please consider marking this topic as [Solved]. See How to mark a topic as [Solved] for a short how-to.
Thanks!

system · November 22, 2025, 12:04am

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