WAN not getting DHCP IP on TP-Link Archer A6 v3

Hi everybody

I have a brand new TP-Link Archer A6 v3 on which I installed (through stock GUI):
openwrt-21.02.0-ramips-mt7621-tplink_archer-a6-v3-squashfs-factory.bin

OpenWRT is up and running with Luci.

If wan port of Archer A6 is connected to LAN port in my former router (ASUS WL-520GC), it gets IP address normally and connects to Internet.
If wan port of Archer A6 is connected directly to "modem" (it is actually a Ubiquiti LiteBeam-M5-23, which works as a router), it does not get IP address.
I have power-cycled both the LiteBeam and Archer A6.
I have modified the MAC address of WAN port on Archer A6 to copy the WL-520GC.
I have tried to force the wan IP on Archer A6 to static on the range of LiteBeam.
I have disabled Archer A6's firewall.
Nothing has worked so far.
If I connect my PC directly to LiteBeam it gets a dynamically assigned IP too and Internet access (without power-cycling the LiteBeam), so the problem is not on MAC level.

I have not acces to LiteBeam's config, because this is owned by my WISP. But, I'm sure there's no need to change anything there, given that my old router and my PC both connect fine to Internet. There must be something that needs to be configured properly on OpenWRT. Being a standard topology and config I don't see why it does not run out of the box...

I'd be greatful for your kind help.
Some further info follows:

root@Archer_A6:~# 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 packet_steering '1'
        option ula_prefix 'fdb5:4035:3c75::/48'

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'
        option proto 'static'
        option netmask '255.255.255.0'
        option ip6assign '60'
        option ipaddr '192.168.35.1'

config interface 'wan'
        option device 'wan'
        option proto 'dhcp'
        option hostname '*'

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

root@Archer_A6:~# 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 packet_steering '1'
        option ula_prefix 'fdb5:4035:3c75::/48'

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'
        option proto 'static'
        option netmask '255.255.255.0'
        option ip6assign '60'
        option ipaddr '192.168.35.1'

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

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

root@Archer_A6:~# 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 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 '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 start '100'
        option limit '150'
        option leasetime '12h'
        option ignore '1'
        list ra_flags 'none'

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

bump

Any more info that I might share and be useful to debug this?

Bump again

If this is helpful to anybody, after reflashing the firmware the issue with the WAN IP address was still there.

So, in further investigation, I came accross several threads that refer to some issue with the WAN interface being down upon reboot, and not being up sufficiently fast to get detected by the counter-party, or something of the like.

Refer to:

As a workaround, for now I have included an ethernet switch between my modem and my router. This forces the WAN interface to be up, and getting its IP from the modem.

I'll try to replicate the eth0 eth1 swapping suggested in the thread above.

I hope this helps someone and avoids some headaches.

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.