LAN and WAN unreachable but DHCP working properly

I ran into a networking issue after a simple router config change while being connected to a local network device over SSH. I guess the router had to restart some things, causing the connection to drop for a few seconds. The connection never properly returned to my Manjaro machine however.

Behavior:

  • The machine is connected over ethernet to the router
  • The network interface correctly gets a leased IP over DHCP
  • I can ping both localhost and the leased IP of the network interface
  • I cannot ping any local network device, including the router (gateway)
  • I cannot ping anything outside the local network (like 8.8.8.8)
  • The router cannot ping the Manjaro machine
  • A Windows installation on the same machine (dual boot) works perfectly fine
> ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether d0:50:99:ad:7b:41 brd ff:ff:ff:ff:ff:ff
3: br-49c3a9bcfc91: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:24:c0:af:5a brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:90:b4:78:4f brd ff:ff:ff:ff:ff:ff
5: br-abf7b7410a5d: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:57:25:5d:c9 brd ff:ff:ff:ff:ff:ff
6: br-d37005efd653: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:04:59:c3:cf brd ff:ff:ff:ff:ff:ff
7: br-0ae9995b562e: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:33:1a:60:34 brd ff:ff:ff:ff:ff:ff
8: br-47117eb5582f: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:16:fa:1f:10 brd ff:ff:ff:ff:ff:ff

> ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether d0:50:99:ad:7b:41 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.20/24 brd 192.168.1.255 scope global dynamic noprefixroute enp0s25
       valid_lft 81367sec preferred_lft 81367sec
    inet6 fe80::e835:189f:ad89:c3e3/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: br-49c3a9bcfc91: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:24:c0:af:5a brd ff:ff:ff:ff:ff:ff
    inet 172.19.0.1/16 brd 172.19.255.255 scope global br-49c3a9bcfc91
       valid_lft forever preferred_lft forever
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:90:b4:78:4f brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
5: br-abf7b7410a5d: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:57:25:5d:c9 brd ff:ff:ff:ff:ff:ff
    inet 172.30.0.1/16 brd 172.30.255.255 scope global br-abf7b7410a5d
       valid_lft forever preferred_lft forever
6: br-d37005efd653: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:04:59:c3:cf brd ff:ff:ff:ff:ff:ff
    inet 172.21.0.1/16 brd 172.21.255.255 scope global br-d37005efd653
       valid_lft forever preferred_lft forever
7: br-0ae9995b562e: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:33:1a:60:34 brd ff:ff:ff:ff:ff:ff
    inet 172.20.0.1/16 brd 172.20.255.255 scope global br-0ae9995b562e
       valid_lft forever preferred_lft forever
8: br-47117eb5582f: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:16:fa:1f:10 brd ff:ff:ff:ff:ff:ff
    inet 172.22.0.1/16 brd 172.22.255.255 scope global br-47117eb5582f
       valid_lft forever preferred_lft forever
       
> ip route
default via 192.168.1.1 dev enp0s25 proto dhcp metric 20100 
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown 
172.19.0.0/16 dev br-49c3a9bcfc91 proto kernel scope link src 172.19.0.1 linkdown 
172.20.0.0/16 dev br-0ae9995b562e proto kernel scope link src 172.20.0.1 linkdown 
172.21.0.0/16 dev br-d37005efd653 proto kernel scope link src 172.21.0.1 linkdown 
172.22.0.0/16 dev br-47117eb5582f proto kernel scope link src 172.22.0.1 linkdown 
172.30.0.0/16 dev br-abf7b7410a5d proto kernel scope link src 172.30.0.1 linkdown 
192.168.1.0/24 dev enp0s25 proto kernel scope link src 192.168.1.20 metric 100 

> ixni -N
Network:   Device-1: Intel Ethernet I218-V driver: e1000e 

> ping -c 3 192.168.1.20
PING 192.168.1.20 (192.168.1.20) 56(84) bytes of data.
64 bytes from 192.168.1.20: icmp_seq=1 ttl=64 time=0.059 ms
64 bytes from 192.168.1.20: icmp_seq=2 ttl=64 time=0.050 ms
64 bytes from 192.168.1.20: icmp_seq=3 ttl=64 time=0.050 ms

--- 192.168.1.20 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2006ms
rtt min/avg/max/mdev = 0.050/0.053/0.059/0.004 ms

> ping -c 3 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
From 192.168.1.20 icmp_seq=1 Destination Host Unreachable
From 192.168.1.20 icmp_seq=2 Destination Host Unreachable
From 192.168.1.20 icmp_seq=3 Destination Host Unreachable

--- 192.168.1.1 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2024ms
pipe 2

> tracepath 192.168.1.1
 1?: [LOCALHOST]                      pmtu 1500
 1:  pc-linux                                    1851.286ms !H
     Resume: pmtu 1500 

So far I’ve tried rebooting, unplugging and reconnecting the network cable, removing and recreating the connection profile through the Manjaro setting GUI, and adding a temporary routing entry to the gateway using ip route add.
Does anyone know anything else I can try?

Hi @TheLuckys, and welcome!

This is the Manjaro forum and should be kept to Manjaro support.

That being said, I’d recommend you use your Windoze installation, since it’s working fine, to log in and access the router and see if there is anything blocked. (It almost sounded like a MAC address block, but you said your Windoze install on the same machine works perfectly, so I don’t think it’s that.)

From this side of the world the only other thing I can recommend is if you’ve done that and there’s nothing there that you can see causing this, is a good old fashioned plug-it-out-and-in-again.

Failing that, I’d recommend a factory reset.

Thank you! And thanks for your very speedy response and suggestions!

I’m terribly sorry if this wasn’t the correct place to post. I’ll try to keep it Manjaro related here and find networking support elsewhere.

Is there any way to only factory reset the network settings in Manjaro? I’d hate to do a fresh install of the entire machine…

I didn’t mean the Manjaro installation. I meant your router. You’ll be able to find instruction by asking the Graet Master of Knowledge, Mr. Google.

I really didn’t think the router was at fault, as it was showing an active connection to the machine running Manjaro, and none of my other devices connected to the network were experiencing any issues (also, “Windoze” running on the same machine was working perfectly fine with the same leased IP address). But low and behold, after a reboot of the router everything is working again…

I’m feeling somewhat ashamed I didn’t try that yet, and to have wasted your valuable time with something so trivial.

I’m just glad it worked!

First rule of troubleshooting, at least for me, is restarting it. And if there are many “its” involved, restart everything!

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