RPI 4b usb to ethernet connection not working [ARCH Linux]

[df3643]

Hi, I apologise if this has been addressed somewhere else.

I am using the RPI 4b headless and I am running a custom Archlinux OS.

I am trying to connect my RPI 4b to my home internet modem/router via a USB2.0 to ethernet connector while also connecting the RPI to a router without an internet connection. The job of this router is to assign IP addresses to other devices in a local network.

RPI 4b ----- Internet (via USB to Ethernet Connector, not sure about the IP address assigned here, as it might be different)

RPI 4b -----Router (via ethernet, gets assigned IP 192.168.0.14)

router ----- connected to an RPI 3 device via Wifi and connected to RPI4b via ethernet.

In this situation, when I try to access the internet website that hosts the RPI 4b I get a partial image of the website and then it tells me that the IP address is not available.

when I switch things around:

RPI 4b ----- Internet (via ethernet port)

RPI 4b -----Router (via USB to Ethernet Connector)

router ----- connected to an RPI 3 device via Wifi and connected to RPI4b via ethernet.

I can see the hosting website is up and running, but the connection to the other devices via the router is not detected.

I am wondering if 1) the USB to ethernet connector is not working properly with the Archlinux OS

2) if having two IP addresses (one from the router and one from my internet modem/router both connected to RPI4b) is confusing the RPI4b.

What can I do to be able to access the host website for the RPI4b while also being able to detect the devices connected to the router?

This has been very difficult for me to figure out, with limited knowledge of RPI, Archlinux and routers. Any help would be appreciated!

[epoch1970]

In all probability: no and no.
Post the output of "ip route", "ip link", "ip address"
And any file where you might be configuring network parameters.

[df3643]

Code: Select all

IP address :
lo<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN node default 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

eth0:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP node DEFAULT group default qlen 1000
link/ether dc:a6:32:59:2b:ec brd ff:ff:ff:ff:ff:ff
inet 192.168.0.14/24 brd 192.168.0.255 scope global dynamic eth0
valid_lft 86337sec preferred_lft 86337sec
inet6 fe80::dea6:32ff:fe59:2bec/64 scope link
valid_lft forever preferred_lft forever

wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether dc:a6:32:59:2b:ed brd ff:ff:ff:ff:ff:ff

enp1s0u1u3:enp1s0u1u3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:d0:e0:a0:ba:9a brd ff:ff:ff:ff:ff:ff

Code: Select all

ip route:

default via 192.168.0.10 dev eth0 proto dhcp src 192.168.0.14 metric 1024
192.168.0.0/24 dev eth0 proto kernal scope link src 192.168.0.14
192.168.0.10 dev eth0 proto dhcp src 192.168.0.14 metric 1024

Code: Select all

ip link:

lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN node default group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP node DEFAULT group default qlen 1000
link/ether dc:a6:32:59:2b:ec brd ff:ff:ff:ff:ff:ff

wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether dc:a6:32:59:2b:ed brd ff:ff:ff:ff:ff:ff

enp1s0u1u3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:d0:e0:a0:ba:9a brd ff:ff:ff:ff:ff:ff

Thanks!

[epoch1970]

Ok. Ethernet is up and nothing else. Is that your issue?

[df3643]

Yes, it could be so. I have two ethernet cables connected to the node (RPI4b), one in the ethernet port that seems to be working. This one is going to the router (see the diagram).
The other ethernet cable is connected via a usb2 to ethernet device to the internet (my local modem/router).

The issue is that when I have things set up this way, I can't access the internet website that the node is hosting.

So it would make sense if only the ethernet port is active since that is the only thing that seems to be working in terms of connecting to the router, but not the internet. Is there a reason why the USB2 is not working? How do I activate it? I thought that it was the USB to ethernet device, but the node (RPI) can see it. Thanks.

[epoch1970]

enp1s0u1u3 is your USB adapter, I assume?
If so it is discovered by the OS but not configured. Configure it.

[df3643]

Yes, I think that this is the USB adapter. What or where would I get the information on how to configure it on RPI 4b?

[epoch1970]

Look for information on how to do that in Arch Linux.
This is not specific to the hardware.