Just installed OpenWRT on my router, but can't make it work

Installing and Using OpenWrt
1

So, just freshly installed OpenWRT but have no idea how and what to configure to make it work. Reading through random topics on the forum and documentation didn't help either. Total newbie so bear with me here.
Also info on my router and initial configuration after restoring to default settings:

{
	"kernel": "6.12.74",
	"hostname": "OpenWrt",
	"system": "MediaTek MT7621 ver:1 eco:4",
	"model": "Xiaomi Redmi Router AC2100",
	"board_name": "xiaomi,redmi-router-ac2100",
	"rootfs_type": "squashfs",
	"release": {
		"distribution": "OpenWrt",
		"version": "25.12.2",
		"firmware_url": "https://downloads.openwrt.org/",
		"revision": "r32802-f505120278",
		"target": "ramips/mt7621",
		"description": "OpenWrt 25.12.2 r32802-f505120278",
		"builddate": "1774469393"
	}
}

uci export dhcp
package 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'
	option ra_slaac '1'
	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/odhcpd.leases'
	option leasetrigger '/usr/sbin/odhcpd-update'
	option loglevel '4'
	option piodir '/tmp/odhcpd-piodir'
	option hostsdir '/tmp/hosts'

uci export firewall
package firewall

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

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'

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'

cat /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 '00042b157e10ac7245cda8de78ff415bb040'
	option ula_prefix 'fdb8:f246:3d31::/48'
	option packet_steering '1'

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

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	list ipaddr '192.168.1.1/24'
	option ip6assign '60'

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

config interface 'wan6'
	option device 'wan'
	option proto 'dhcpv6'
2

If you mean that internet is not working try changing the lan ip address from 192.168.1.1/24 to 192.168.2.1/ 24

So change the third octet and not the fourth

If you are using LuCi (the graphical interface) then click on the little down arrow on the right side of the save & apply button and choose Apply anyway so do not revert after 90 sec

After that reboot router and PC.

You should then be able to login to the router at the new address.

Hopefully this works if not you have to give more details about upstream so what is connected to the wan

3

I assume when you say it "does not work" you mean that your LAN devices cannot reach the Internet. Clearly you can obtain LAN IP addresses and log into the router so that part is working.

What type of ISP connection do you have? The default settings should work with cable and most fiber ISPs. A DHCP connection is also called IPoE.

Run ifstatus wan or examine the main status page of the GUI (Upstream IPv4) to see if there is a connection to the ISP. And as @egc said, if your upstream IP address is 192.168.1.X you will need to change the LAN to a different IP range for routing to work.

5

I changed the address as you advised but the result is the same, still can't ping/nslookup anything. About ISP connection type, it's fiber. Don't know what other information is relevant in this situation. Also checked the WAN status, i'm not sure if it works as supposed but it has ip and gateway so i guess it's connected alright

6

what are the first two octets (in bold aaa.bbb.ccc.ddd) of the IPv4 address you see on the wan?

7

It's 10.115.xxx.xxx

8

Ok... that is not a public IP, which means your ISP is likely providing a CG-NAT type environment (technically this isn't the CG-NAT range, but it's the same idea).

If you use the diagnostics in the OpenWrt router, what happens? Specifically, try pinging 8.8.8.8 and then openwrt.org.

9

So if i ping 8.8.8.8 and then openwrt.org:

PING 8.8.8.8 (8.8.8.8): 56 data bytes

--- 8.8.8.8 ping statistics ---
5 packets transmitted, 0 packets received, 100% packet loss

ping: bad address 'openwrt.org'

the result is the same if i firstly ping openwrt.org and 8.8.8.8 after.

traceroute:

traceroute to 8.8.8.8 (8.8.8.8), 20 hops max, 46 byte packets
 1  10.115.19.129  0.661 ms !N

traceroute: bad address 'openwrt.org'

nslookup:

Server:		127.0.0.1
Address:	127.0.0.1:53

** server can't find 8.8.8.8.in-addr.arpa: REFUSED

Server:		127.0.0.1
Address:	127.0.0.1:53

** server can't find openwrt.org: REFUSED

** server can't find openwrt.org: REFUSED
10

Power down the ISP modem and power down the openwrt router
After 3 minitues power up the ISP router and after 3 more minutes power up de openwrt router then check again.

If that does not help connect your PC directly to the ISP modem and see if you have internet, note the ip of your PC (from cmd: ipconfig /all)

11

I'm not sure if i can access ISP modem. I just have a wire connected to my router and after that it goes who knows where out of my apartment

12

Then connect the wire to your PC and see if you have internet and what your IP address is

13

So to make sure i understand everything correctly. I supposed to put the wan cable into my PC and check if i have connection?

14

yes indeed

15

Tried to connect this way but still no internet connection. Checked ip address it's in the same range as my router was when it was connected to wan (something like 10.115.19.xxx)

16

Did you try from your PC also with ping 8.8.8.8?
If that also fails the problem is with your ISP router and you should contact your ISP provider.
Check with your provider if bridge mode is possible and how to setup your own router if the ISP router is in bridge mode.

17

Yeah i tried pinging and it's all 100% packet loss. So i gonna contact my ISP then, i will tell the result afterwards

18

Alrighty... So the ISP guy wasn't too helpful in finding a solution. His advice is to revert to the stock firmware and call him to deal with it instead of dealing with OpenWRT. My plan is to follow his advice and just get internet finally working in my apartment and then just buy another router to install openwrt on

19

As @egc told you, it is very unlikely this is an openwrt issue, it is your ISP's miscofiguration. Putting OEM firmware on your router may make the support person more comfortable but it will not help. I would suggest to connect your PC to the ISP gateway and tell the support "I am not going to use a router, I am going to use just one Windows/Mac machine directly connected to your gateway". Once they fixed the problem (and again, 99.99% chance the problem is with their configurations, not with you router or PC), you can connect your router, openwrt or not.

20

Alrighty... So the whole thing is finally over. In the end the ISP guy just needed to configure PPPoE and that was it. And i decided not to revert anything and keep openwrt on my router. Just wanna say thank you to everyone for cooperation! Much obliged!