[AndreasT]

Router: Asus RT-AC3200
DD-wrt build: v3.0-r36168

Problem:
After the initial setup the router does not do NAT or DHCP and devices on the LAN receive WAN public adresses from the ISP.
I am no expert on this, but it seems to me that the router is in switch or bridge mode even if it is set to gateway.
I can not connect to the router after boot. If I disconnect the ISP modem and reboot, the router responds to 10.0.1.1 as usual.
The Connection type is set to the default DHCP.

I include a screenshot of the VLAN settings, which I think is at their default.
The WAN port is set to VLAN2 in the port setup, as per default.

Here are the vlan settings in nvram:
nvram show |grep vlan
size: 39291 bytes (91781 left)
vlan2_hwaddr=2C:4D:54:00:CA:91
vlan2_mtu=1500
vlan1_label=
vlan1_ipaddr=0.0.0.0
bat_vlan1_bridge=br0
vlan2ports=4 5u
vlan1_isolation=0
port5vlans=1 2 16
vlan1_txq=1000
port3vlans=1 18 19 21
vlan2_ipaddr=0.0.0.0
vlan2_multicast=0
port1vlans=1 18 19 21
bat_vlan2_bridge=br0
wl0_vlan_prio_mode=off
vlan2hwname=et0
wan_ifname2=vlan2
vlan1_bridged=1
vlan2_nat=1
vlan1_dns_ipaddr=0.0.0.0
vlan1_netmask=0.0.0.0
vlan2_isolation=0
lan_ifnames=vlan1 vlan2 eth1 eth2 eth3
wan_default=vlan2
vlan1_mtu=1500
vlan1hwname=et0
vlan1ports=0 1 2 3 5*
vlan2_txq=1000
wl2_vlan_prio_mode=off
vlan2_bridged=1
port4vlans=1 18 19 21
vlans=1
vlan_tagcount=0
port2vlans=1 18 19 21
vlan2_dns_redirect=0
vlan2_label=
vlan2_netmask=0.0.0.0
port0vlans=2 18 19 21
probe_blacklist=vlan1 vlan2 eth0
landevs=vlan1 wl0 wl1 wl2
dtag_vlan8=0
vlan2_dns_ipaddr=0.0.0.0
vlan1_hwaddr=2C:4D:54:00:CA:90
vlan_tags=
vlan1_multicast=0
vlan1_dns_redirect=0
wl1_vlan_prio_mode=off
vlan1_nat=1

I appreciate any help you can give.

[Dr_K]

Your Vlan page matches at least 2 of my R6300v2's setup as gateways

I believe -n and newer devices uses vlan2 for WAN while older pre -n,b/g devices used vlan1 for WAN.....
At least thats what the wiki says https://wiki.dd-wrt.com/wiki/index.php/Default_Configuration_Overview

[AndreasT]

Ok thanks.
Haven’t made any changes yet. As for trying things blindly, I have tried searching for any info on what the default vlan settings are for this router, and have come up empty. I assume the defaults are what is displayed, though I cannot rule out that there may be some remnant in the nvram from the previous firmware, even though I did the reset procedure and got the fast flashing power led as confirmation. Thanks for the link, I saw it before but couldn’t understand it. I understand more now.
Looking for any other advice on how fix the issue.

[Dr_K]

[AndreasT]

[AndreasT]

Looking through postings about this router, I see several people reporting that the wan and lan 1 ports are switched around and other issues with the default physical port mapping. This could explain a lot in my case.
I will check this tomorrow.

[Dr_K]

[AndreasT]

I'm happy to report that the issue was solved by remapping the ports. The WAN port and LAN1 port were indeed switched and when I plugged the WAN cable into the LAN1 port, I got it working. The router was indeed working as a switch.

This was the erroneous default mappings on this router: