[Solved] Cannot access internet after upgrade

d4eva · February 21, 2026, 4:54pm

Hi,
After I upgraded my router, I could not access internet. When I performed the restore from backup, I created before the upgrade, internet worked again.

This started to happen some releases ago (I don't remember exactly), and each time I was able to get it working and I was hoping that issue would be solved in the next major version, but it wasn't

So this time I created a backup of a non working/working configs and compared them.
There's a difference in 2 files

/etc/config/dhcp

Non working:

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 authoritative '1'
	option readethers '1'
	option leasefile '/tmp/dhcp.leases'
	option localservice '1'
	option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'

config dhcp 'lan'
	option interface 'lan'
	option start '100'
	option limit '150'
	option leasetime '12h'
	option dhcpv6 'server'
	option ra 'server'
	option ra_management '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 host
	option mac '00:A0:DE:B4:57:A6'
	option name 'yamaha'
	option dns '1'
	option ip '192.168.1.128'

config host
	option mac 'C8:5B:76:94:07:50'
	option dns '1'
	option name 'Lenovo'
	option ip '192.168.1.146'

config host
	option mac 'E8:6A:64:1A:DA:EF'
	option name 'P50'
	option dns '1'
	option ip '192.168.1.141'

config host
	option mac 'D0:67:E5:42:97:49'
	option name 'sdclap020'
	option dns '1'
	option ip '192.168.1.106'

config host
	option mac '00:06:78:38:5C:36'
	option ip '192.168.1.149'
	option name 'Denon'
	option dns '1'

config host
	option mac 'B4:2E:99:44:F0:C7'
	option name 'Erix-PC'
	option dns '1'
	option ip '192.168.1.140'

Working:

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 authoritative '1'
	option readethers '1'
	option leasefile '/tmp/dhcp.leases'
	option localservice '1'
	option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'

config dhcp 'lan'
	option interface 'lan'
	option start '100'
	option limit '150'
	option leasetime '12h'
	option dhcpv6 'server'
	option ra 'server'
	option ra_management '1'

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'

config host
	option mac '00:A0:DE:B4:57:A6'
	option name 'yamaha'
	option dns '1'
	option ip '192.168.1.128'

config host
	option mac 'C8:5B:76:94:07:50'
	option dns '1'
	option name 'Lenovo'
	option ip '192.168.1.146'

config host
	option mac 'E8:6A:64:1A:DA:EF'
	option name 'P50'
	option dns '1'
	option ip '192.168.1.141'

config host
	option mac 'D0:67:E5:42:97:49'
	option name 'sdclap020'
	option dns '1'
	option ip '192.168.1.106'

config host
	option mac '00:06:78:38:5C:36'
	option ip '192.168.1.149'
	option name 'Denon'
	option dns '1'

config host
	option mac 'B4:2E:99:44:F0:C7'
	option name 'Erix-PC'
	option dns '1'
	option ip '192.168.1.140'

And
/etc/config/network

Non working:

config interface 'loopback'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'
	option device 'lo'

config globals 'globals'
	option ula_prefix 'fdd9:b7c4:0fab::/48'
	option dhcp_default_duid '00043e03ae42080f46e299a50e4e20fe46b5'

config interface 'lan'
	option proto 'static'
	option netmask '255.255.255.0'
	option ip6assign '60'
	option ipaddr '192.168.1.2'
	option device 'br-lan'

config interface 'wan'
	option proto 'dhcp'
	option device 'br-wan'

config device 'wan_eth0_2_dev'
	option name 'eth0.2'
	option macaddr '1c:3b:f3:50:2b:a1'

config interface 'wan6'
	option proto 'dhcpv6'
	option device 'eth0.2'

config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'

config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '2 3 4 5 0t'

config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '1 0t'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0.1'
	option igmp_snooping '1'

config device
	option name 'br-wan'
	option type 'bridge'

Working:


config interface 'loopback'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'
	option device 'lo'

config globals 'globals'
	option ula_prefix 'fdd9:b7c4:0fab::/48'

config interface 'lan'
	option proto 'static'
	option netmask '255.255.255.0'
	option ip6assign '60'
	option ipaddr '192.168.1.2'
	option device 'br-lan'

config interface 'wan'
	option proto 'dhcp'
	option device 'eth0.2'
	option type 'bridge'

config device 'wan_eth0_2_dev'
	option name 'eth0.2'
	option macaddr '1c:3b:f3:50:2b:a1'

config interface 'wan6'
	option proto 'dhcpv6'
	option device 'eth0.2'

config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'

config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '2 3 4 5 0t'

config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '1 0t'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0.1'
	option igmp_snooping '1'

My device

ubus call system board
{
        "kernel": "6.12.71",
        "hostname": "TP_AC1750",
        "system": "Qualcomm Atheros QCA956X ver 1 rev 0",
        "model": "TP-Link Archer C7 v5",
        "board_name": "tplink,archer-c7-v5",
        "rootfs_type": "squashfs",
        "release": {
                "distribution": "OpenWrt",
                "version": "25.12.0-rc5",
                "firmware_url": "https://downloads.openwrt.org/",
                "revision": "r32673-482ba7230a",
                "target": "ath79/generic",
                "description": "OpenWrt 25.12.0-rc5 r32673-482ba7230a",
                "builddate": "1771363837"
        }
}

lleachii · February 21, 2026, 5:05pm

Not sure why you're concerned about the non working config now - but try removing this.

psherman · February 21, 2026, 5:10pm

Can you provide the difference directly? In other words, please show us the specific line(s) at issue in addition to the full context so that we don't have to scrub through the two versions searching for the diffs.

That said, the bridge on the wan is certainly unusual and typically shouldn't be there as @lleachii pointed out.

d4eva · February 21, 2026, 5:15pm

Here are the diffs.

For dhcp

For network

psherman · February 21, 2026, 5:16pm

Please post those -- in text form -- directly into the forum itself.

d4eva · February 21, 2026, 5:21pm

dhcp:

Non working:

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'

Where it works:

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

network:

Non working - this one has some extra rows:

config globals 'globals'
	option ula_prefix 'fdd9:b7c4:0fab::/48'
	option dhcp_default_duid '00043e03ae42080f46e299a50e4e20fe46b5'

config interface 'wan'
	option proto 'dhcp'
	option device 'br-wan'

config device
	option name 'br-wan'
	option type 'bridge'

Where it works:

config globals 'globals'
	option ula_prefix 'fdd9:b7c4:0fab::/48'


config interface 'wan'
	option proto 'dhcp'
	option device 'eth0.2'
	option type 'bridge'

lleachii · February 21, 2026, 5:26pm

Did you make these edits?

Same question. Otherwise, the WAN bridge configuration is likely the culprit.

Just use the working config. I surmise that you're just inquing to learn and understand.

psherman · February 21, 2026, 5:30pm

This is the reason for the problem...

In the above, you have an empty bridge - no ports assigned. Then the empty bridge is used in the wan network interface... the result is that there is no internet/wan connectivity via Ethernet.

The above is largely correct in that there is a valid Ethernet device (eth0.2). But the bridge line should not be there. Remove that.

Now, the question really is: how did the non-working config end up there? It's certainly not what would be found in the default config. Further, I don't see how it's possible that it worked at all, unless you had a wireless upstream connection.

d4eva · February 21, 2026, 6:25pm

I removed the bridge row and it's still working, so I will leave it like this.
It might be some leftover from my configuration experiments some time ago.
Anyway, thanks.

psherman · February 21, 2026, 6:32pm

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!

fkl7834456 · February 22, 2026, 11:06am

Pay attention to the eth0.2 interface, in new versions it has changed to wan. Reset the settings and configure the router from scratch to avoid any issues.

psherman · February 22, 2026, 4:10pm

This does not apply to swconfig devices. The hardware in question is ath79 and still on swconfig.