Still struggling setting up my new O-Wrt router/AP environment.
Using four O-WRT routers. One connected to the ISP device in client mode. ISP device is on pppoe mode. Connected via WAN port, when stand-alone means ISP device and the router all is ok, Internet is stable LAN and WLAN.
This ISP connected router also configured following the official guide. No extras!
Problem occurs as soon I am connecting my network via LAN to that first O-Wrt router.
Immediately Internet isn't working anymore. Means off/on within a few seconds.
Connecting means three further O-Wrt routers via switches and Ethernet.
All three O-Wrt routers configured as dumb APs as shown in the guide. I expected that should work out of the box...
What can cause this issue?
How can I analyze?
Let’s take a look at your configs.
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have:
ubus call system board
cat /etc/config/network
cat /etc/config/wireless
cat /etc/config/dhcp
cat /etc/config/firewall
You mean from the main router, that one connected as client via WAN to the Zyxel ISP device?
Here it is.
This is the standalone router just connected some devices WLAN and one laptop via LAN.
Please let me know when you would need the same when connected to the network or from another AP.
Just coming in my mind I see a lot of DHCPv6 entries and I remember when setting up the other APs three entries something for DHCPv6 were set to disabled.
OpenWrt 24.10.1, r28597-0425664679
-----------------------------------------------------
root@OpenWrt:~# ubus call system board
{
"kernel": "6.6.86",
"hostname": "OpenWrt",
"system": "ARMv8 Processor rev 4",
"model": "Cudy WR3000S v1",
"board_name": "cudy,wr3000s-v1",
"rootfs_type": "squashfs",
"release": {
"distribution": "OpenWrt",
"version": "24.10.1",
"revision": "r28597-0425664679",
"target": "mediatek/filogic",
"description": "OpenWrt 24.10.1 r28597-0425664679",
"builddate": "1744562312"
}
}
root@OpenWrt:~# 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 ula_prefix 'xxxx'
option packet_steering '1'
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 ipaddr '192.168.2.1'
option netmask '255.255.255.0'
option ip6assign '60'
config interface 'wan'
option device 'wan'
option proto 'dhcp'
config interface 'wan6'
option device 'wan'
option proto 'dhcpv6'
root@OpenWrt:~# cat /etc/config/wireless
config wifi-device 'radio0'
option type 'mac80211'
option path 'platform/soc/18000000.wifi'
option band '2g'
option channel '9'
option htmode 'HE20'
option cell_density '0'
option country 'DE'
config wifi-iface 'default_radio0'
option device 'radio0'
option network 'lan'
option mode 'ap'
option ssid 'D4'
option encryption 'psk2'
option key 'xxxx
config wifi-device 'radio1'
option type 'mac80211'
option path 'platform/soc/18000000.wifi+1'
option band '5g'
option channel '36'
option htmode 'HE80'
option cell_density '0'
option country 'DE'
config wifi-iface 'default_radio1'
option device 'radio1'
option network 'lan'
option mode 'ap'
option ssid 'D5'
option encryption 'psk2'
option key 'xxxx
root@OpenWrt:~# cat /etc/config/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 '101'
option limit '200'
option leasetime '12h'
option dhcpv4 'server'
option dhcpv6 'server'
option ra 'server'
list ra_flags 'managed-config'
list ra_flags 'other-config'
option force '1'
config dhcp 'wan'
option interface 'wan'
option ignore '1'
option start '100'
option limit '150'
option leasetime '12h'
config odhcpd 'odhcpd'
option maindhcp '0'
option leasefile '/tmp/hosts/odhcpd'
option leasetrigger '/usr/sbin/odhcpd-update'
option loglevel '4'
root@OpenWrt:~# cat /etc/config/firewall
config defaults
option syn_flood 1
option input REJECT
option output ACCEPT
option forward REJECT
# Uncomment this line to disable ipv6 rules
# option disable_ipv6 1
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 REJECT
option masq 1
option mtu_fix 1
config forwarding
option src lan
option dest wan
# We need to accept udp packets on port 68,
# see https://dev.openwrt.org/ticket/4108
config rule
option name Allow-DHCP-Renew
option src wan
option proto udp
option dest_port 68
option target ACCEPT
option family ipv4
# Allow IPv4 ping
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
# Allow DHCPv6 replies
# see https://github.com/openwrt/openwrt/issues/5066
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
# Allow essential incoming IPv6 ICMP traffic
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
# Allow essential forwarded IPv6 ICMP traffic
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
### EXAMPLE CONFIG SECTIONS
# do not allow a specific ip to access wan
#config rule
# option src lan
# option src_ip 192.168.45.2
# option dest wan
# option proto tcp
# option target REJECT
# block a specific mac on wan
#config rule
# option dest wan
# option src_mac 00:11:22:xxxx
# option target REJECT
# block incoming ICMP traffic on a zone
#config rule
# option src lan
# option proto ICMP
# option target DROP
# port redirect port coming in on wan to lan
#config redirect
# option src wan
# option src_dport 80
# option dest lan
# option dest_ip 192.168.16.235
# option dest_port 80
# option proto tcp
# port redirect of remapped ssh port (22001) on wan
#config redirect
# option src wan
# option src_dport 22001
# option dest lan
# option dest_port 22
# option proto tcp
### FULL CONFIG SECTIONS
#config rule
# option src lan
# option src_ip 192.168.45.2
# option src_mac 00:11:22:xxxx
# option src_port 80
# option dest wan
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
# option target REJECT
#config redirect
# option src lan
# option src_ip 192.168.45.2
# option src_mac 00:11:22:xxxx
# option src_port 1024
# option src_dport 80
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
root@OpenWrt:~#
To complete the picture, this is the config from one of the three APs.
All configured simultaneously.
Just to mention these three O-WRT APs are currently running attached via a switch to my Telekom Landline DSL router (No O-WRT).
Means exactly that config is running there error free.
As soon as I change the Router and attach the etherenet cable to the O-WRT router, Internet is more or less gone, as mentioned On/Off within seconds intervall.
-----------------------------------------------------
OpenWrt 23.05.5, r24106-10cc5fcd00
-----------------------------------------------------
root@OpenWrt:~# ubus call system board
{
"kernel": "5.15.167",
"hostname": "OpenWrt",
"system": "MediaTek MT7628AN ver:1 eco:2",
"model": "TP-Link Archer C50 v4",
"board_name": "tplink,archer-c50-v4",
"rootfs_type": "squashfs",
"release": {
"distribution": "OpenWrt",
"version": "23.05.5",
"revision": "r24106-10cc5fcd00",
"target": "ramips/mt76x8",
"description": "OpenWrt 23.05.5 r24106-10cc5fcd00"
}
}
root@OpenWrt:~# 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 ula_prefix 'xxxx'
config device
option name 'br-lan'
option type 'bridge'
list ports 'eth0.1'
config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.2.3'
option netmask '255.255.255.0'
option ip6assign '60'
option gateway '192.168.2.1'
list dns '192.168.2.1'
config device
option name 'eth0.2'
option macaddr '50:d4:xxxx'
config interface 'wan'
option device 'eth0.2'
option proto 'dhcp'
config interface 'wan6'
option device 'eth0.2'
option proto 'dhcpv6'
config switch
option name 'switch0'
option reset '1'
option enable_vlan '1'
config switch_vlan
option device 'switch0'
option vlan '1'
option ports '1 2 3 4 6t'
config switch_vlan
option device 'switch0'
option vlan '2'
option ports '0 6t'
root@OpenWrt:~# cat /etc/config/wireless
config wifi-device 'radio0'
option type 'mac80211'
option path 'platform/10300000.wmac'
option channel '1'
option band '2g'
option htmode 'HT20'
option cell_density '0'
option country 'DE'
config wifi-iface 'default_radio0'
option device 'radio0'
option network 'lan'
option mode 'ap'
option ssid 'SEK'
option encryption 'psk2'
option key 'xxxx'
config wifi-device 'radio1'
option type 'mac80211'
option path 'pci0000:00/0000:00:00.0/0000:01:00.0'
option channel '60'
option band '5g'
option htmode 'VHT40'
option cell_density '0'
option country 'DE'
config wifi-iface 'default_radio1'
option device 'radio1'
option network 'lan'
option mode 'ap'
option ssid 'SEK'
option encryption 'psk2'
option key 'xxxx'
root@OpenWrt:~# cat /etc/config/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 ignore '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'
root@OpenWrt:~# cat /etc/config/firewall
config defaults
option syn_flood 1
option input REJECT
option output ACCEPT
option forward REJECT
# Uncomment this line to disable ipv6 rules
# option disable_ipv6 1
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 REJECT
option masq 1
option mtu_fix 1
config forwarding
option src lan
option dest wan
# We need to accept udp packets on port 68,
# see https://dev.openwrt.org/ticket/4108
config rule
option name Allow-DHCP-Renew
option src wan
option proto udp
option dest_port 68
option target ACCEPT
option family ipv4
# Allow IPv4 ping
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
# Allow DHCPv6 replies
# see https://github.com/openwrt/openwrt/issues/5066
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
# Allow essential incoming IPv6 ICMP traffic
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
# Allow essential forwarded IPv6 ICMP traffic
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
### EXAMPLE CONFIG SECTIONS
# do not allow a specific ip to access wan
#config rule
# option src lan
# option src_ip 192.168.45.2
# option dest wan
# option proto tcp
# option target REJECT
# block a specific mac on wan
#config rule
# option dest wan
# option src_mac 00:11xxxx
# option target REJECT
# block incoming ICMP traffic on a zone
#config rule
# option src lan
# option proto ICMP
# option target DROP
# port redirect port coming in on wan to lan
#config redirect
# option src wan
# option src_dport 80
# option dest lan
# option dest_ip 192.168.16.235
# option dest_port 80
# option proto tcp
# port redirect of remapped ssh port (22001) on wan
#config redirect
# option src wan
# option src_dport 22001
# option dest lan
# option dest_port 22
# option proto tcp
### FULL CONFIG SECTIONS
#config rule
# option src lan
# option src_ip 192.168.45.2
# option src_mac 00:11:xxxx
# option src_port 80
# option dest wan
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
# option target REJECT
#config redirect
# option src lan
# option src_ip 192.168.45.2
# option src_mac 00:11:xxxxx
# option src_port 1024
# option src_dport 80
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
root@OpenWrt:~# ^C
root@OpenWrt:~#
The only error I see here is the dhcp server on the main router:
The limit is too high - it must be <=154 given your start value of 101. And the force line should not be required. If it is, you have a rogue dhcp server running on the network.
Can you describe in detail what you mean by this?
Do you have an Ethernet loop issue, by any chance?
No, I don´t think I do have a Ethernet loop. I do use three switches and they are in sequence from the Router to the first switch from there to the roof switch and here again down to ground floor. And it works when connected to the still existent Telekom DSL router (Non-O-WRT) no issues.
As said all APs are already on O-WRT (one config I just attached) and when connected to the old DSL landline router all working stable.
The only reason why I would like to change is that I can increase internet speed a lot with 5G access.
When I change the main router and just plug that one ethernet cable from the Telekom DSL router into the O-WRT router (same static IP) internet is gone!
LAN and WLAN signal keeps strong and stable but internet goes on and off.
Easy to see on the android mobile phone when the WIFI signal icon gets an exclamation mark showing that no Internet available in choosen Wlan.
I thought that there is maybe the IPv6 config different, at least I read some comments when checking the config for the Zyxel 5G router.
The force line I tried not knowing what to do, will change that back as well as the limit to 150, no issue.
Let me know when I should check something else, maybe some log?
One further idea!
What would I loose when plugging the ISP router into the LAN1 instead WAN port?
What would I need to change in the O-WRT router?
My understanding, please correct me when I am wrong:
- Change to AP instead of client
- Firewall needs to be activated in the ISP router, is it required to be activated in the O-WRT router as well?
- DHCP can be performed by the O-WRT router and need to be deactivated for the ISP router
- I assume need to set DNS and Gateway for all other APs to that "first" AP next to the ISP router serving DHCP
- Will I get trouble with IPv6 with such a setup?
- What about all the other features I planned to use like Wireguard client and host or VLAN will that work when attaching on LAN1 instead of WAN?
I just connected my network again to the O-WRT router and same trouble, it takes a minute and internet is gone on LAN and WLAN. in the system log I only can see these warnings, is that of interest?
Sun May 4 18:49:24 2025 daemon.warn odhcpd[1824]: No default route present, overriding ra_lifetime to 0!
Sun May 4 18:49:49 2025 daemon.warn odhcpd[1824]: No default route present, overriding ra_lifetime to 0!
Sun May 4 18:49:49 2025 daemon.warn odhcpd[1824]: No default route present, overriding ra_lifetime to 0!
Sun May 4 18:50:38 2025 daemon.info dnsmasq[1]: read /etc/hosts - 12 names
Sun May 4 18:50:38 2025 daemon.info dnsmasq[1]: read /tmp/hosts/dhcp.cfg01411c - 4 names
Sun May 4 18:50:38 2025 daemon.info dnsmasq[1]: read /tmp/hosts/odhcpd - 2 names
Sun May 4 18:50:38 2025 daemon.info dnsmasq-dhcp[1]: read /etc/ethers - 0 addresses
Sun May 4 18:50:39 2025 daemon.info dnsmasq[1]: read /etc/hosts - 12 names
Sun May 4 18:50:39 2025 daemon.info dnsmasq[1]: read /tmp/hosts/dhcp.cfg01411c - 4 names
Sun May 4 18:50:39 2025 daemon.info dnsmasq[1]: read /tmp/hosts/odhcpd - 2 names
Sun May 4 18:50:39 2025 daemon.info dnsmasq-dhcp[1]: read /etc/ethers - 0 addresses
Sun May 4 18:50:40 2025 daemon.warn odhcpd[1824]: No default route present, overriding ra_lifetime to 0!
Sun May 4 18:51:30 2025 daemon.info dnsmasq-dhcp[1]: DHCPDISCOVER(br-lan) 70:3xxx
Sun May 4 18:51:30 2025 daemon.info dnsmasq-dhcp[1]: DHCPOFFER(br-lan) 192.168.2.224 70:3xxxx
Sun May 4 18:51:30 2025 daemon.info dnsmasq-dhcp[1]: DHCPREQUEST(br-lan) 192.168.2.224 70:3xxxx
Sun May 4 18:51:30 2025 daemon.info dnsmasq-dhcp[1]: DHCPACK(br-lan) 192.168.2.224 70:3xxxx
That's interesting but:
show 15 lines before you plug in the OpenWrt router and the 5 after errors stop.
but the rest is just this DHCP discover, offer and ...
The only interesting part was exactly that what i copied and I thought it might telling you something.
What does it mean No default route present, overriding ra_lifetime to 0
Is that maybe a trigger for these internet signal losses I am facing?
Just to add, there is no further error or warning in the system log, that is realy crazy.
Can I maybe check any other log or parameter what tells something about internet signal and transfer into the LAN?
No idea; that's why I'm looking for something that makes sense.
And the error is in the logs.
I have to explain this every so often but routers are not filled with ethereal pixie dust and errors are logged.
So, I need to see some errors and what's clean before and after.
Or
we can post guesses...?
Start one component at a time.
Using a laptop, a single openwrt router, and your dsl modem do the following:
plug in dsl modem, and openwrt router and laptop into a lan port on the openwrt router. Verify internet connectivity. Unplug laptop and configure laptop to wifi. Verify internet connectivity.
Plug in ethernet hub to openwrt router with nothing else plugged in. turn off wifi on laptop and plug laptop into etherhet hub. Verify connectivity. unlug laptop and turn on wifi. associate and verify connectivity.
Plug in second hub and repeat.
Plug in 3rd hub and repeat
Plug in first ethernet device into first hub and repeat
continue plugging ethernet devices into hub and test each time until all devices plugged in and everything is still working.
Go to second hub and repeat until all devices plugged in
Go to 3rd hub and repeat until all devices plugged in
Now, introduce the first openwrt router you want to use as an AP into the network by plugging it in to whatever hub it's in, and repeat testing
Continue doing this methodically, one item at a time, giving PLENTY of time in between each test to make sure network is stable.
Eventually you will plug in some device that will cause the entire network to collapse. There's your culprit.
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