Simple issue: Connecting 2 devices to same router

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello, newbie here.

I have computer 1 and computer 2.
Computer 1 is connected to router with OpenWrt: lan port1. Everything works fine.
Computer 2 is connected to same router lan port2. Computer 2 cannot access the internet.

I assume its a simple dhcp config thing, but cannot distinguish the issue from myriad of options in LuCI settings.
Computer 2 works fine if connected to lan port1.
OpenWrt Logs says " Interface 'lan2' has link connectivity" if I toggle network adapter on/off. So the port is not busted or mislabeled.

Logs also say : daemon.warn dnsmasq-dhcp[1]: DHCP packet received on lan2 which has no address

Question is: How to make both computers have fluid internet access at same time?
Maybe some subnet masking best practices while we at it?

tnx.

2
  • Type of device?
  • OpenWrt version?
  • Did you make any network config changes?
  • Does this work on OpenWrt when reset to defaults?
3

OpenWrt 22.03.2
Router: Asus RT-AC56U
Computers : Windows 10 / 8/ debian 11

I installed samba, so could access HDD connected to router. And a bunch of dependencies to it. But didnt change Network settings before connecting computer 2.

After the conenction issue, i did try adding static ip tho. And toggling Authorative DHCP. Clearly having no idea what I was doing.

4
  • You listed 3 OSes. Which is Computer 1 and Computer 2?
  • :bulb: Does plugging any computer into Port 2 fail?

Please provide /etc/config/network

On machine not wokring, provide output of:

  • If Windows tracert 8.8.8.8
  • If Linux traceroute 8.8.8.8
5

  • Any computer with any OS connected to port 2 fails to connect to internet.

  • I don't know how to provide /etc/config/network .

  • tracert 8.8.8.8 on a windows machine conencted to port2 gives the following =
    1 transmit error : code 1231

6

Wow, not good. I was thinking that.

(Seems unrelated...but...)

What is the result with Linux?

  • SSH to router and run cat /etc/config/network - or
  • In web GUI - backup your config, open the archive and browse/extract /etc/config/network
7

ok thanks.

here the results


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 'fd00:95d5:45d4::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'eth0'
	list ports 'eth1'
	list ports 'eth2'
	list ports 'lan1'
	list ports 'lan2'
	list ports 'lan3'
	list ports 'lan4'
	list ports 'wan'

config interface 'lan'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'
	list dns '84.200.69.80'
	list dns '84.200.70.40'
	option delegate '0'
	option device 'lan1'

config device
	option name 'wan'
	option macaddr 'BC:EE:7B:8e:3c:b9'

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

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

config interface 'lan2'
	option device 'lan2'
	option proto 'static'

config device
	option name 'lan2'
	option ipv6 '0'
	option acceptlocal '1'

config device
	option name 'eth2'
	option ipv6 '0'

config route
	option interface 'lan2'
	option type 'local'
	option target '192.168.1.0/24'
	option gateway '192.168.1.1'
1 Like
8

On the working machine on port 1 :

traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  192.168.195.2 (192.168.195.2)  0.130 ms  0.060 ms  0.107 ms
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *
 9  * * *
10  * * *
11  * * *
12  * * *
13  * * *
14  * * *
15  * * *
16  * * *
17  * * *
18  * * *
19  * * *
20  * * *
21  * * *
22  * * *
23  * * *
24  * * *
25  * * *
26  * * *
27  * * *
28  * * *
29  * * *
30  * * *
9

Working machine, and the working port?

Ummmmm...do you (or your ISP) have traceroute blocked?

(I was recommending traceroute as a utility to test connectivity on both ports - but that result from Port 1 suggests it won't be helpful.)

:bulb: I'm starting to think you physical port 2 is bad.

Your device has 4 LAN ports, is there a reason you're not discussing the working condition of Ports 3 and 4???

:warning: WAN port attached to LAN and WAN - is definitely not the default config!

  • Editing posts to add information/configs can be confusing - I didn't notice this edit at first
  • Did you add/edit these list port stanzas?
2 Likes
10

That config is a real mess. I don't know exactly what it should be on the Broadcom platform that you have, but for certain when a port is in a bridge it must not be also referred to separately, which is being done with lan2. Have a lan network with br-lan as its device, and all the ports that you want to attach to LAN devices in that bridge. This will become clear when you revert to the default configuration.

11

ehh yes :sweat_smile:, i have tried alot of configs since trying to fix the problem.
sorry I meant the problem was there before I made edits.

Well, now I managed to lock the whole device, cannot log in from ssh and all network connections was lost.

So I did a hard reset by pressing down the reset button for 11 seconds.

Now it works.

Lost all the samba settings tho, which is a pain to set up again.

12

This seemed to have been the issue. Took a while to wrap my head around how that works.

I imagine the flow chart going like :
Internet-> WAN port (make dhcp client) ->br-lan [internal bridge (make static adress)] -> lan1 and lan2(from Network Interfaces Settings: Devices: br-lan Configurations: Bridge ports: select the switch ports: "lan1", "lan2" )

13

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