I've been trying to get my Beaglebone Black to connect to internet using an ethernet cable plugged direct into my Netgear router. I have tried many things but nothing has worked so far. Here are some relevant outputs. systemctl # Yesterday, internet not working ● networking.service loaded failed failed Raise network interfaces # Today after reflashing beaglebone, internet still not working networking.service loaded active exited Raise network interfaces ip address 1: lo: 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: can0: mtu 16 qdisc noop state DOWN group default qlen 10 link/can 3: can1: mtu 16 qdisc noop state DOWN group default qlen 10 link/can 4: eth0: mtu 1500 qdisc mq state UP group default qlen 1000 link/ether a0:f6:fd:8a:ec:7e brd ff:ff:ff:ff:ff:ff inet 192.168.0.10/24 brd 192.168.0.255 scope global eth0 valid_lft forever preferred_lft forever inet 192.168.0.123/24 brd 192.168.0.255 scope global secondary eth0 valid_lft forever preferred_lft forever inet6 2600:8806:502:b00:a2f6:fdff:fe8a:ec7e/64 scope global mngtmpaddr dynamic valid_lft 86390sec preferred_lft 86390sec inet6 fe80::a2f6:fdff:fe8a:ec7e/64 scope link valid_lft forever preferred_lft forever ip route default via 192.168.0.1 dev eth0 68.105.28.11 via 192.168.0.1 dev eth0 68.105.28.12 via 192.168.0.1 dev eth0 68.105.29.11 via 192.168.0.1 dev eth0 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.10 192.168.0.1 dev eth0 scope link 192.168.6.0/30 dev usb1 proto kernel scope link src 192.168.6.2 linkdown 192.168.7.0/30 dev usb0 proto kernel scope link src 192.168.7.2 linkdown 212.227.81.55 via 192.168.0.1 dev eth0 host google.com ;; connection timed out; no servers could be reached ping www.google.com ping: www.google.com: Temporary failure in name resolution ping 192.168.0.1 (router) PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data. --- 192.168.0.1 ping statistics --- 9 packets transmitted, 0 received, 100% packet loss, time 8199ms ping 192.168.0.39 (my computer, connected to same router via ethernet) PING 192.168.0.39 (192.168.0.39) 56(84) bytes of data. 64 bytes from 192.168.0.39: icmp_seq=1 ttl=64 time=0.432 ms 64 bytes from 192.168.0.39: icmp_seq=2 ttl=64 time=0.324 ms 64 bytes from 192.168.0.39: icmp_seq=3 ttl=64 time=0.389 ms 64 bytes from 192.168.0.39: icmp_seq=4 ttl=64 time=0.387 ms --- 192.168.0.39 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3004ms rtt min/avg/max/mdev = 0.324/0.383/0.432/0.038 ms I have no idea how to fix this. It started working yesterday when I started writing this question then it started working mysteriously. I rebooted this morning and it's not working again.

I have a problem with my wired ethernet connection on a Dell Inspiron 5593 with Ubuntu 20.04. When I try to connect it keeps asking me for the password continuously. Wired connection work fine with windows operating system. Running **lspci**

00:00.0 Host bridge: Intel Corporation Device 8a12 (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Iris Plus Graphics G7 (rev 07)
00:04.0 Signal processing controller: Intel Corporation Device 8a03 (rev 03)
00:14.0 USB controller: Intel Corporation Ice Lake-LP USB 3.1 xHCI Host Controller (rev 30)
00:14.2 RAM memory: Intel Corporation Device 34ef (rev 30)
00:15.0 Serial bus controller [0c80]: Intel Corporation Ice Lake-LP Serial IO I2C Controller #0 (rev 30)
00:15.1 Serial bus controller [0c80]: Intel Corporation Ice Lake-LP Serial IO I2C Controller #1 (rev 30)
00:16.0 Communication controller: Intel Corporation Management Engine Interface (rev 30)
00:17.0 SATA controller: Intel Corporation Ice Lake-LP SATA Controller [AHCI mode] (rev 30)
00:19.0 Serial bus controller [0c80]: Intel Corporation Ice Lake-LP Serial IO I2c Controller #4 (rev 30)
00:1d.0 PCI bridge: Intel Corporation Ice Lake-LP PCI Express Root Port #9 (rev 30)
00:1d.1 PCI bridge: Intel Corporation Device 34b1 (rev 30)
00:1d.4 PCI bridge: Intel Corporation Device 34b4 (rev 30)
00:1f.0 ISA bridge: Intel Corporation Ice Lake-LP LPC Controller (rev 30)
00:1f.3 Audio device: Intel Corporation Smart Sound Technology Audio Controller (rev 30)
00:1f.4 SMBus: Intel Corporation Ice Lake-LP SMBus Controller (rev 30)
00:1f.5 Serial bus controller [0c80]: Intel Corporation Ice Lake-LP SPI Controller (rev 30)
01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL810xE PCI Express Fast Ethernet controller (rev 07)
02:00.0 Network controller: Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter (rev 31)
03:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd Device a809

Running **ifconfig**:

enp1s0: flags=4099  mtu 1500
        ether 98:e7:43:23:ee:98  txqueuelen 1000  (Ethernet)
        RX packets 428  bytes 88040 (88.0 KB)
        RX errors 0  dropped 124  overruns 0  frame 0
        TX packets 11  bytes 198 (198.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
lo: flags=73  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 11433  bytes 1017879 (1.0 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 11433  bytes 1017879 (1.0 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
wlp2s0: flags=4163  mtu 1500
        inet 192.168.43.134  netmask 255.255.255.0  broadcast 192.168.43.255
        inet6 fe80::82e7:348:ff4f:ef24  prefixlen 64  scopeid 0x20
        ether 40:23:43:c8:91:53  txqueuelen 1000  (Ethernet)
        RX packets 2689989  bytes 3915552343 (3.9 GB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1395506  bytes 130709369 (130.7 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Running **nmcli device**:

*DEVICE          TYPE      STATE         CONNECTION   
wlp2s0          wifi      connected     Quick Hospot 
p2p-dev-wlp2s0  wifi-p2p  disconnected  --           
enp1s0          ethernet  unavailable   --           
lo              loopback  unmanaged     --

(when ethernet cable is plugged in, it shows "connecting" on enp1s0 state) Running **route**:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         _gateway        0.0.0.0         UG    600    0        0 wlp2s0
link-local      0.0.0.0         255.255.0.0     U     1000   0        0 wlp2s0
192.168.43.0    0.0.0.0         255.255.255.0   U     600    0        0 wlp2s0

Running **dmesg**: https://pastebin.com/PG7yZdYw I tried different solutions but nothing has worked.

I have an ethernet cable connected to my home server but I have no internet connection despite the interface having status UP. I cannot even ping the router (at 192.168.10.1). When I plug the same cable into a different computer the connection works as expected. How can I troubleshoot this? I tried to consult ChatGPT and follow its suggestions but it did not lead to a solution. I can also mention that I have no functioning WiFi due to driver problems so currently I access the server through a serial console (with Minicom). $ ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group defau0 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 noprefixroute valid_lft forever preferred_lft forever 2: end0: mtu 1500 qdisc fq_codel state UP gro0 link/ether d0:63:b4:00:97:0e brd ff:ff:ff:ff:ff:ff inet 192.168.142.34/24 brd 192.168.142.255 scope global dynamic end0 valid_lft 6341sec preferred_lft 6341sec inet 192.168.142.32/24 brd 192.168.142.255 scope global secondary end0 valid_lft forever preferred_lft forever inet6 2a02:aa1:1158:d95a:d263:b4ff:fe00:970e/64 scope global dynamic mngtmp valid_lft forever preferred_lft forever inet6 fe80::d263:b4ff:fe00:970e/64 scope link valid_lft forever preferred_lft forever 3: wlan0: mtu 1500 qdisc fq_codel s0 link/ether 4c:aa:16:fe:ca:f7 brd ff:ff:ff:ff:ff:ff $ uname -a Linux server 6.1.0-37-armmp #1 SMP Debian 6.1.140-1 (2025-05-22) armv7l GNU/Linx **Requested additional information:** $ ip route 0.0.0.0 dev end0 scope link default dev end0 scope link 37.247.0.55 dev end0 scope link 37.247.0.56 dev end0 scope link 192.168.142.0/24 dev end0 proto kernel scope link src 192.168.142.34 $ sudo traceroute 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets 1 * * * 2 * * * 30 * * * $ networkctl WARNING: systemd-networkd is not running, output will be incomplete. IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback - unmanaged 2 end0 ether - unmanaged 3 wlan0 wlan - unmanaged 3 links listed. $ ls /etc/network/interfaces* /etc/network/interfaces /etc/network/interfaces.bak /etc/network/interfaces.d: $ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface allow-hotplug end0 iface end0 inet dhcp

I'm having a hard time automating loading a gadget module and bringing up the usb0 device as a eth interface. The interface in question is g_ether for a embedded Linux device and connecting to a PC. I imagine there is a way to see the event from the plugin and run a script with udev. When I plug my device into a PC, I don't see any events. I tried different variations of udevadm monitor and I'm not sure how to find out what I can use as a udev rule to modprobe a gadget module. Part of the reason I'm trying to load the otg module is because we are mostly using g_ether. I want to use avahi-autoipd but its getting an IP address before its plugged in. If I use allow-hotplug in the network interface it never automatically brings the interface up when its plugged in. So in theory, I want to plug in the device to a PC, run avahi-autoipd on the new network interface to retrieve an IP, and dhcpd to give one to the host. Since someone else starting helping me in the stackoverflow (reposting here) I've got some more info. /sys/bus/usb/devices$ ls 1-0:1.0 2-0:1.0 3-0:1.0 3-1 3-1:1.0 usb1 usb2 usb3 [ 4297.515400] g_ether gadget: high speed config #2: RNDIS [ 4300.379021] g_ether gadget: high speed config #1: CDC Ethernet (ECM) sys/bus/usb/devices$ ls 1-0:1.0 2-0:1.0 3-0:1.0 3-1 3-1:1.0 usb1 usb2 usb3 I've tried running udevadm monitor --environment udevadm monitor --environment --udev udevadm monitor udevadm monitor --kernel udevadm monitor --kernel --udev unplugging and plugging the device in doesn't show anything. The manpage says it " Listens to the kernel uevents and events sent out by a udev rule" and I have no rules on my device. So I'm assuming that's probably why nothing prints out ever, even if I try to do some things with other hardware? I'm running an embedded Linux distribution. I imagine I might not have everything a desktop has? Its come to my attention I might have an issue with my g_ether module? These outputs never change. cat /sys/class/net/usb0/carrier cat: read error: Invalid argument cat /sys/class/net/usb0/operstate down

I wanted to know if there is a way to differentiate physical and virtual network devices. ip a doesn't have an option. So I am trying /sys/class/net/. There are 2 attributes addr_assign_type and type, but type only tells Ethernet or loopback there is not way to tell if its virtual. I wanted to know does addr_assign_type tell us the different? As per my observation /sys/class/net//{eth|loopback} gives 0 and /sys/class/net//{virtualdevice} gives 1 or 3. Is there something I can infer from this?

I currently have a linux system with only one physical ethernet port. This physical port has the eth0 network interface attached to it. I want to create another ethernet interface which also makes use of this single physical port. How could I achieve this using the /etc/network/interfaces file? My ultimate goal is to be able to access two different networks using a single ethernet port. For example, if I have the following interfaces file:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
        address 192.168.1.11
        netmask 255.255.255.0
        gateway 192.168.1.1

auto eth1
iface eth1 inet static
        address 192.168.16.100
        netmask 255.255.255.0
        gateway 192.168.16.1

I would expect to be able to ping both networks, but so far I can only ping eth0 even if I am pinging eth1 from the right network (192.168.16.0/24). I am sure I am missing some sort of configuration since it would seem too easy to simply add a new entry in the interfaces file and hope that it magically works. I am aware that I can add multiple IPs to a single ethernet interface using the command ip addr add 192.168.16.100/24 dev eth0 but I would very much prefer to have two separate interfaces. Thanks!

I have connected an embedded board to a usb0 interface of a Linux machine to establish a ssh connection to it. ifconfig tells me: usb0 Link encap:Ethernet HWaddr 16:43:4D:AA:E8:5A inet addr:192.168.2.5 Bcast:192.168.2.255 Mask:255.255.255.0 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) But it is not "RUNNING". How can I start the interface? Is there a driver missing? lsusb finds the device. The device itself runs Yocto Linux.

Recently I've got a bit odd idea and did some googling but found nothing (Closest is this super user question but I think my idea is not the same). The idea is, as I think, relatively simple and kinda lies on the surface so I'm surprised there's nothing about it out there. The question is: is it possible to divide one physical 8-terminal ethernet port into 2 by 4? The idea came to my mind because I've got one Raspberry Pi with one ethernet port and I thought could I use it as a kind of poor hardware firewall? I've got a server at home and the cable that goes from my ISP is 4-pinned, so I thought to make a cable that would have 3 heads, with one in the middle, so that one would go from my ISP and connect to the Raspberry Pi and by the same connector, but with other terminals connect to my router. Maybe it would require writing/patching an ethernet driver or something, but I'm just curious

I am having a strange problem trying to get network working on Linux using systemd. My network eth0 is connected to a corporate network with a DHCP server:

# more /etc/systemd/network/main.network

#Main connection to the outside world
[Match]
Name=eth0
[Network]
DHCP=yes 
IPForward=yes

# networkctl status eth0

2: eth0
           Link File: n/a
        Network File: /etc/systemd/network/main.network
                Type: ether
               State: routable (configured)
          HW Address: 00:03:2d:32:85:3a (IBASE Technology, Inc.)
                 MTU: 1500
             Address: 10.0.7.134
                      fe80::203:2dff:fe32:853a
             Gateway: 10.0.7.1
                 DNS: 10.0.7.10

However, wait-online service fails:

# /lib/systemd/systemd-networkd-wait-online --interface eth0 --timeout=10

ignoring: sit0
Event loop failed: Connection timed out

The system had acquired a valid IP address on eth0 so I don't understand why it would not be online. I have another interface in the system, eth1, that is not plugged in.

I have two Ubuntu 22.04.05 LTS server with Mellanox CX-6 nic with 25Gbps link. I found very strange behavior with ipef3 when using HWE kernel. I have default MTU 1500 # uname -a Linux mcc-ceph207-02 5.15.0-131-generic #141-Ubuntu SMP Fri Jan 10 21:18:28 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux iperf3 result # iperf3 -c 10.230.35.130 Connecting to host 10.230.35.130, port 5201 [ 5] local 10.230.35.131 port 34384 connected to 10.230.35.130 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 2.56 GBytes 22.0 Gbits/sec 0 3.08 MBytes [ 5] 1.00-2.00 sec 2.24 GBytes 19.2 Gbits/sec 361 1.55 MBytes [ 5] 2.00-3.00 sec 2.72 GBytes 23.4 Gbits/sec 0 1.57 MBytes [ 5] 3.00-4.00 sec 2.73 GBytes 23.5 Gbits/sec 0 1.81 MBytes [ 5] 4.00-5.00 sec 2.73 GBytes 23.5 Gbits/sec 0 1.86 MBytes [ 5] 5.00-6.00 sec 2.73 GBytes 23.5 Gbits/sec 0 1.86 MBytes [ 5] 6.00-7.00 sec 2.31 GBytes 19.9 Gbits/sec 0 1.98 MBytes [ 5] 7.00-8.00 sec 2.51 GBytes 21.6 Gbits/sec 0 2.03 MBytes [ 5] 8.00-9.00 sec 2.73 GBytes 23.5 Gbits/sec 0 2.03 MBytes [ 5] 9.00-10.00 sec 2.73 GBytes 23.5 Gbits/sec 0 2.03 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 26.0 GBytes 22.3 Gbits/sec 361 sender [ 5] 0.00-10.04 sec 26.0 GBytes 22.2 Gbits/sec receiver Now installed HWE kernel on same box and result is very different # uname -a Linux mcc-ceph207-01 6.8.0-52-generic #53~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jan 15 19:18:46 UTC 2 x86_64 x86_64 x86_64 GNU/Linux iperf3 result # iperf3 -c 10.230.35.130 Connecting to host 10.230.35.130, port 5201 [ 5] local 10.230.35.131 port 44400 connected to 10.230.35.130 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 1.87 GBytes 16.1 Gbits/sec 472 1.33 MBytes [ 5] 1.00-2.00 sec 1.85 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 2.00-3.00 sec 1.86 GBytes 16.0 Gbits/sec 0 1.33 MBytes [ 5] 3.00-4.00 sec 1.86 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 4.00-5.00 sec 1.85 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 5.00-6.00 sec 1.86 GBytes 16.0 Gbits/sec 0 1.33 MBytes [ 5] 6.00-7.00 sec 1.86 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 7.00-8.00 sec 1.85 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 8.00-9.00 sec 1.85 GBytes 15.9 Gbits/sec 0 1.33 MBytes [ 5] 9.00-10.00 sec 1.85 GBytes 15.9 Gbits/sec 0 1.33 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 18.6 GBytes 15.9 Gbits/sec 472 sender [ 5] 0.00-10.04 sec 18.6 GBytes 15.9 Gbits/sec receiver

OS: CentOS 6.6 / 64bit / Kernel 2.6.32-504.30.3.el6.x86_64 I have bond0 interface with following configuration. Ethernet Channel Bonding Driver: v3.6.0 (September 26, 2009) Bonding Mode: IEEE 802.3ad Dynamic link aggregation Transmit Hash Policy: layer2 (0) MII Status: up MII Polling Interval (ms): 100 Up Delay (ms): 0 Down Delay (ms): 0 802.3ad info LACP rate: slow Aggregator selection policy (ad_select): stable Active Aggregator Info: Aggregator ID: 7 Number of ports: 2 Actor Key: 17 Partner Key: 3 Partner Mac Address: a4:56:30:c6:0d:00 Slave Interface: eth0 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 2 Permanent HW addr: 9c:8e:99:0d:1a:f2 Aggregator ID: 7 Slave queue ID: 0 Slave Interface: eth1 MII Status: up Speed: 1000 Mbps Duplex: full Link Failure Count: 2 Permanent HW addr: 9c:8e:99:0d:1a:f4 Aggregator ID: 7 Slave queue ID: 0 modprobe.conf alias bond0 bonding options bond0 mode=4 miimon=100 Cisco switch config: interface Port-channel1 description Linux-bond0 switchport access vlan 10 interface GigabitEthernet0/7 switchport access vlan 10 spanning-tree portfast spanning-tree guard root channel-protocol lacp channel-group 1 mode active ! interface GigabitEthernet0/8 switchport access vlan 10 spanning-tree portfast spanning-tree guard root channel-protocol lacp channel-group 1 mode active ! # Issue I am getting RX packet drop on bond0 and eth0 interface on Linux ( but not on eth1) bond0 : RX packets:575214161 errors:0 dropped:6407 overruns:0 frame:0 eth0 : RX packets:573623915 errors:0 dropped:6410 overruns:0 frame:0 eth1 : RX packets:1590356 errors:0 dropped:0 overruns:0 frame:0 I have check MRTG to see traffic flow and its around ~30mbps But interesting thing. I am seeing all 30mbps traffic on eth0, eth1 has few kbps traffic. That means my link is not doing load balancing right? cacti reporting following data. LACP should share traffic on both link right? eth0: 30mbps eth1: 600kbps

System is Ubuntu 16.10. It has been updated quite some times, so it might have some remaining stuff from earlier versions in there (at least back till 14.04, probably much longer). The issue it the following: I have two network interfaces in the system (on mainboard). One was always named eth0. The second was not in use. Now I have a new situation in my network and want to use the second interface. I learned a lot about interface rename and the new rename rules. So the second interface choses the name enp5s0 or similar, can't remember, therefore I need to rename it. But here is where my trouble starts. eth0 was handled in /etc/udev/rules.d/70-persistent-net.rules which, I learned, is deprecated. I tried to add a second rule for "eth1" there (using its mac instead the one of eth0), but it did not work. So after reading a bit I got rid of the old file and maybe I misunderstood something, but I figured eth* names are discouraged today, so I've chosen to call them lan0 and lan1 (which describes what they will be used for). Then I added new files in /etc/systemd/network:

10-eth-lan0.link
10-eth-lan1.link

With this content:

[Match]
MACAddress=00:23:54:96:74:07/06

[Link]
Name=lan0/1

for the different MACAddresses and the different names. For eth0 this seems to work, for eth1 (or whatever reason) it does not. And I am quite puzzled why the heck it won't work. I tripple checked the mac. dmesg | grep eth shows me this:

[    6.233684] sky2 0000:08:00.0 eth0: addr 00:23:54:96:74:07
[    6.233975] sky2 0000:05:00.0 eth1: addr 00:23:54:96:74:06
[    6.661954] sky2 0000:08:00.0 lan0: renamed from eth0
[    8.513836] sky2 0000:05:00.0 rename3: renamed from eth1

I have absolutely no clue why it settled for "rename3" now... I experimented a bit with ip link set name after I saw the systemd link file not working. What puzzles me most is that it works for eth0 -> lan0 but not for eth1 -> lan1. What can I look into to find out why the rename is not working? Who is caching stuff here? The "ip link set name" did have some persistent effects (like the change to "rename3" from the enp5s0 or similar). [edit] I recognized one more thing now: My loopback interface gets renamed to lan1. Don't know why. But it happens on every boot now. Also I got rid of the *.link files described above and the renames still happen just the same.... ??? In /etc there is now just one mention of lan0 in /etc/network/interfaces and no mention of lan1. Somebody stores that stuff somewhere and I don't know who or where.

I'm stuck with an audio problem. I have an old machine (let's call it Alice) under Xubuntu, that I can use to continuously listen sounds from an external microphone plugged in the line-in jack. I can access the machine from my PC (let's call it Bob -under Ubuntu) with ssh (and physically too ... when I will update the login keyboard layout that changed recently I don't know why, and currently prevents me from doing so). I've tried to remotely record the microphone, unsuccessfully, with arecord, pulseaudio, but I'm new with ALSA and PA. With PA the mic isn't listed with pacmd list-sources!?. Is there a (simple?) way I can continuously (but in the same time, I don't have much space on the disk, max 50 GB free) record on Alice (and eventually read the records from Bob)?

I am looking for a way to prevent eth0 interface from adding a default route to my main routing table on my Linux machine. I have a Debian distribution (Jessie - 8.0) and was looking at the post-up directive in /etc/network/interfaces. My current configuration looks as follows: **ifconfig** eth0 Link encap:Ethernet HWaddr b8:27:eb:4b:f4:9e inet addr:172.16.2.82 Bcast:172.16.3.255 Mask:255.255.252.0 inet6 addr: fe80::ba27:ebff:fe4b:f49e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2311 errors:0 dropped:0 overruns:0 frame:0 TX packets:203 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:187402 (183.0 KiB) TX bytes:22251 (21.7 KiB) ppp0 Link encap:Point-to-Point Protocol inet addr:10.178.142.185 P-t-P:192.200.1.21 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:36 errors:0 dropped:0 overruns:0 frame:0 TX packets:56 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3 RX bytes:2918 (2.8 KiB) TX bytes:3426 (3.3 KiB) **/etc/network/interfaces** auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp post-up /sbin/route del default dev eth0 **ip route show table main** default dev ppp0 scope link default via 172.16.0.40 dev eth0 metric 202 10.64.64.65 dev ppp1 proto kernel scope link src 10.181.104.9 169.254.0.0/16 dev wlan0 proto kernel scope link src 169.254.23.201 metric 303 169.254.0.0/16 dev wwan0 proto kernel scope link src 169.254.62.145 metric 305 172.16.0.0/22 dev eth0 proto kernel scope link src 172.16.2.160 metric 202 192.168.42.0/24 dev wlan0 proto kernel scope link src 192.168.42.1 192.200.1.21 dev ppp0 proto kernel scope link src 10.179.96.79 Sadly, this approach only works if the interface is brought up using ifup eth0, and not when the cable is physically connected and ip assigned. Even still, this approach doesn't delete the default entry and ifup gives the following error: Internet Systems Consortium DHCP Client 4.3.1 Copyright 2004-2014 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/b8:27:eb:4b:f4:9e Sending on LPF/eth0/b8:27:eb:4b:f4:9e Sending on Socket/fallback DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6 DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11 DHCPREQUEST on eth0 to 255.255.255.255 port 67 DHCPOFFER from 172.16.0.8 DHCPACK from 172.16.0.8 eminstBootdpxeboot.com option - discarded eminstBootdpxeboot.com option - discarded bound to 172.16.2.82 -- renewal in 12663 seconds. SIOCDELRT: No such process Failed to bring up eth0. I would like to know a proper way to ensure that the default route is not added through eth0 and **not** have to bring up eth0 manually using ifup (to leverage post-up) but rather use the one that is already initialized on boot.

According to lspci, one of my Linux machines has "Intel Corporation Ethernet Connection X553 10 GbE SFP+" holes. I bought a Ubiquiti SFP RJ45 adapter, but the ixgbe device driver says they're unsupported. This is a Qotom brand fanless server running up-to-date Arch Linux, kernel 6.13.12-hardened1-2-hardened. Both the in-kernel-tree ixgbe device and a self-compiled ixgbe 6.1.3, downloaded from the Intel web site, give the same error, here's dmesg output when I loaded the 6.1.3 Intel driver:

[ 1290.001874] ixgbe: loading out-of-tree module taints kernel.
[ 1290.001913] ixgbe: module verification failed: signature and/or required key missing - tainting kernel
[ 1290.047828] Intel(R) 10GbE PCI Express Linux Network Driver - version 6.1.3
[ 1290.047839] Copyright (C) 1999 - 2025 Intel Corporation
[ 1290.052272] ixgbe 0000:0b:00.0 0000:0b:00.0 (uninitialized): allow_unsupported_sfp Enabled
[ 1290.096489] ixgbe 0000:0b:00.0: failed to load because an unsupported SFP+ or QSFP module type was detected.
[ 1290.096497] ixgbe 0000:0b:00.0: Reload the driver after installing a supported module.

I loaded ixgbe modules like this:

modprobe -v ./ixgbe.ko allow_unsupported_sfp=1

As near as I can tell from reading the source code, allow_unsupported only applies to certain Intel PCIe ethernet devices. I didn't realize this was too much of a thing, so I hadn't really researched it. Now that I have tried, my question is: How Do I find RJ45 SFP adapters that are compatible to Intel X553s? DuckDuckGo and Google don't have much to offer but some Intel forum posts from 10 years ago.

I've searched all related questions to this topic, to no avail. I've got an ethernet card on my laptop, but the connection will not work. I checked in the BIOS, and the card is enabled. I can't undestand why mncli list my ethernet connection as "unavailable"... Here are below the results of different command I used to investigate the issue. I used Linux Mint on a Dell Latitude e5520. Any advise highly appreciated. Best regards, MC

mc@mc-Latitude-E5520:~$ lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
[...]
09:00.2 Mass storage controller: O2 Micro, Inc. O2 Flash Memory Card (rev 05)
0a:00.0 Ethernet controller: Broadcom Inc. and subsidiaries NetXtreme BCM5761 Gigabit Ethernet PCIe (rev 10)

mc@mc-Latitude-E5520:~$  sudo lshw -c network -sanitize
  *-network                 
       description: Wireless interface
       product: Centrino Advanced-N 6205 [Taylor Peak]
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlan0
       version: 34
       serial: [REMOVED]
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=6.8.0-58-generic firmware=18.168.6.1 6000g2a-6.ucode ip=[REMOVED] latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:27 memory:e5300000-e5301fff
  *-network
       description: Ethernet interface
       product: NetXtreme BCM5761 Gigabit Ethernet PCIe
       vendor: Broadcom Inc. and subsidiaries
       physical id: 0
       bus info: pci@0000:0a:00.0
       logical name: enp10s0
       version: 10
       serial: [REMOVED]
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=6.8.0-58-generic firmware=5761-v3.78 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:30 memory:e4110000-e411ffff memory:e4100000-e410ffff

mc@mc-Latitude-E5520:~$ ip a
1: lo:  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 noprefixroute 
       valid_lft forever preferred_lft forever
2: enp10s0:  mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether d0:67:e5:34:4a:16 brd ff:ff:ff:ff:ff:ff
3: wlan0:  mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether a0:88:b4:b2:b8:c0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.40/24 brd 192.168.1.255 scope global dynamic noprefixroute wlan0
       valid_lft 42747sec preferred_lft 42747sec
    inet6 2a01:e0a:b55:b420:2cf2:f8bb:5484:1f9e/64 scope global temporary dynamic 
       valid_lft 86140sec preferred_lft 85723sec
    inet6 2a01:e0a:b55:b420:1f08:4448:2f2f:c436/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 86140sec preferred_lft 86140sec
    inet6 fe80::b80:ca0c:1458:40d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
mc@mc-Latitude-E5520:~$ ip r
default via 192.168.1.254 dev wlan0 proto dhcp src 192.168.1.40 metric 600 
192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.40 metric 600 

mc@mc-Latitude-E5520:~$ sudo  nmcli device
DEVICE   TYPE      STATE                   CONNECTION       
wlan0    wifi      connected               Freebox-5C7A7D 1 
lo       loopback  connected (externally)  lo               
enp10s0  ethernet  unavailable             --               
mc@mc-Latitude-E5520:~$ nmcli con show
NAME                UUID                                  TYPE      DEVICE 
Freebox-5C7A7D 1    7f9fb305-48f8-4547-bf6b-965830a9d664  wifi      wlan0  
lo                  1ad9e920-362a-459e-831d-02e79abba496  loopback  lo     
Freebox-5C7A7D      e78dddb9-7d34-4233-94bb-430b67d424c0  wifi      --     
GLORIOUS EVOLUTION  8cbbc124-2599-4247-b1cc-0fbdd2dd131e  wifi      --     
Maia's Galaxy A12   1ad8128c-afd8-4030-9f60-79a20d719ca6  wifi      --     
Wired connection 1  6bcb00fe-a7d6-3778-bcbf-85def4429cb4  ethernet  --     
mc@mc-Latitude-E5520:~$ sudo nmcli -f all connection 
NAME                UUID                                  TYPE      TIMESTAMP   TIMESTAMP-REAL                    AUTOCONNECT  AUTOCONNECT-PRIORITY  READONLY  DBUS-PATH                                   ACTIVE  DEVICE  STATE      ACTIVE>
Freebox-5C7A7D 1    7f9fb305-48f8-4547-bf6b-965830a9d664  wifi      1746012961  Wed 30 Apr 2025 01:36:01 PM CEST  yes          0                     no        /org/freedesktop/NetworkManager/Settings/4  yes     wlan0   activated  /org/f>
lo                  1ad9e920-362a-459e-831d-02e79abba496  loopback  1746012957  Wed 30 Apr 2025 01:35:57 PM CEST  no           0                     no        /org/freedesktop/NetworkManager/Settings/1  yes     lo      activated  /org/f>
Freebox-5C7A7D      e78dddb9-7d34-4233-94bb-430b67d424c0  wifi      1746010526  Wed 30 Apr 2025 12:55:26 PM CEST  yes          0                     no        /org/freedesktop/NetworkManager/Settings/6  no      --      --         --    >
GLORIOUS EVOLUTION  8cbbc124-2599-4247-b1cc-0fbdd2dd131e  wifi      1735586099  Mon 30 Dec 2024 08:14:59 PM CET   yes          0                     no        /org/freedesktop/NetworkManager/Settings/5  no      --      --         --    >
Maia's Galaxy A12   1ad8128c-afd8-4030-9f60-79a20d719ca6  wifi      1735661656  Tue 31 Dec 2024 05:14:16 PM CET   yes          0                     no        /org/freedesktop/NetworkManager/Settings/2  no      --      --         --    >
Wired connection 1  6bcb00fe-a7d6-3778-bcbf-85def4429cb4  ethernet  0           never                             yes          1                     no        /org/freedesktop/NetworkManager/Settings/3  no      --      --         --    >

I had to install a dkms package to add ethernet support to my Zorin OS (which is Ubuntu 22.04 LTS based) running on an ASUS NUC 14 Essential mini PC . This worked fine for a while but after rebooting, the ethernet connection now started showing "Cable unplugged" in the Network Settings. I've removed the cable and plugged it back in, both on the PC and the wall. I've tried the cable directly with another PC and it works fine, so I'm sure the cable is fine. lspci --nnk shows: 1:00.0 Ethernet controller : Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev ff) Kernel driver in use: r8125 Kernel modules: r8125 ifconfig shows: enp1s0: flags=4099 mtu 1500 ether 48:21:0b:6e:ee:6c txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 18 I installed the driver using the launchpad instructions here : sudo apt install realtek-r8125-dkms dkms status shows: r8125/9.007.01, 6.8.0-57-generic, x86_64: installed (WARNING! Diff between built and installed module!) realtek-r8125/9.015.00, 6.8.0-57-generic, amd64: installed It seems that rebooting has caused some setting to change that was previously working but I'm unsure what it is. I recall that I had to add a module key that had to be entered on the first time reboot after installing the driver, but I've not been asked for that subsequently. At this point, I'm beat. I have a nice working setup so I don't want to reinstall the OS from scratch unless absolutely necessary so any suggestions would be welcome. For now I'm using the wi-fi connection which works.

I'm trying to set up Ethernet on a university pc with Ubuntu 16.04. There are university wide proxy, and I connected 2 other windows PC's to it using .reg file, proxy adress, port and login, password, which I was provided by the university. I tried setting proxy adress and port, using gui (as I did for windows) but it's just doesn't work. Firefox says "Unable to find the proxy server" or sometimes "we're having trouble finding that site" and ping 8.8.8.8 says "Network is unreachable" ping google.com says "unknown host".

says:

enp6s0    Link encap:Ethernet  HWaddr 1c:6f:65:91:3e:4a     
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1   
          RX packets:13462119 errors:0 dropped:16 overruns:0 frame:0   
          TX packets:351453 errors:0 dropped:0 overruns:0 carrier:0   
          collisions:0 txqueuelen:1000    
          RX bytes:893149471 (893.1 MB)  TX bytes:71061986 (71.0 MB)   
   
lo        Link encap:Local Loopback     
          inet addr:127.0.0.1  Mask:255.0.0.0   
          inet6 addr: ::1/128 Scope:Host   
          UP LOOPBACK RUNNING  MTU:65536  Metric:1   
          RX packets:6683368 errors:0 dropped:0 overruns:0 frame:0   
          TX packets:6683368 errors:0 dropped:0 overruns:0 carrier:0   
          collisions:0 txqueuelen:1000    
          RX bytes:494614018 (494.6 MB)  TX bytes:494614018 (494.6 MB)

All 3 PC's are connected to the same lan hub and I tried to switch ports and cables around and nothing changed, on windows internet works and on linux it doesn't. Also, for some reason connection just turnes off every couple minutes or so. Lan cable 100% works. first time Linux user, any help would be of great use. .reg file contains: [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings] "AutoDetect"=dword:00000000 "MigrateProxy"=dword:00000001 "ProxyEnable"=dword:00000001 "ProxyServer"="my_proxy_ip:3128" "ProxyOverride"="some sites" (redacted proxy ip and override just in case)

After an IP address is assigned to this network interface, with any of the the following commands: ip addr add 10.0.0.0 dev eth1 valid_lft forever preferred_lft forever ip addr replace 10.0.0.0 dev eth1 valid_lft forever preferred_lft forever ip addr add 10.0.0.0 dev eth1 ip addr replace 10.0.0.0 dev eth1 I can verify with ip addr that the IP address for eth1 is set to 10.0.0.0/32 which is excellent (I think): ... 3: eth1: mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000 link/ether 08:00:27:4d:1e:43 brd ff:ff:ff:ff:ff:ff inet 10.0.0.0/32 scope global eth1 valid_lft forever preferred_lft forever inet6 fe80::a00:27ff:fe4d:1e43/64 scope link tentative dadfailed valid_lft forever preferred_lft forever ... I begin to ping myself...the ping command hangs on the 31st ping: username@computer:~$ ping 10.0.0.0 PING 10.0.0.0 (10.0.0.0) 56(84) bytes of data. 64 bytes from 10.0.0.0: icmp_seq=1 ttl=64 time=0.043 ms 64 bytes from 10.0.0.0: icmp_seq=2 ttl=64 time=0.034 ms ... 64 bytes from 10.0.0.0: icmp_seq=30 ttl=64 time=0.038 ms 64 bytes from 10.0.0.0: icmp_seq=31 ttl=64 time=0.041 ms Once the ping hangs, I can verify with ip addr that the IP address for eth1 is has disappeared: ... 3: eth1: mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000 link/ether 08:00:27:4d:1e:43 brd ff:ff:ff:ff:ff:ff inet6 fe80::a00:27ff:fe4d:1e43/64 scope link tentative dadfailed valid_lft forever preferred_lft forever ... **How can one assign a static IP address to a network interface using ip(8), and not let it disappear?** (disappearing after system restart is OK) I am running Ubuntu 14.04. From researching on the Internet about my problem, it seems that modifying the file /etc/network/interfaces is the solution, but this is undesirable, because this solution is not as portable as the ip(8) command.

I have two debian based machines with IP adresses XXX.XXX.8.76/26 and XXX.XXX.8.77/26. Now i need to create a tap0 interface on both machines for an application that communicates with UDP messages. But it is not possible for me to send a UDP messages between both tap0's. tap0 eno1 eno1 tap0 I simply created the tap0 with ip tuntap add dev tap0 mode tap After this I bridge the tap0 and the physical ethernet adapter with the following script:

#!/bin/bash

# Exit on error
set -e

# Define variables
BRIDGE=br0
ETH_IFACE=eno1
TAP_IFACE=tap0
IP_ADDR=XXX.XXX.8.76/26
GATEWAY=XXX:XXX.8.65  

# Check if run as root
if [ "$EUID" -ne 0 ]; then 
  echo "Please run as root"
  exit
fi

echo "Creating bridge $BRIDGE..."
ip link add $BRIDGE type bridge

echo "Bringing up the bridge..."
ip link set $BRIDGE up

echo "Adding $ETH_IFACE and $TAP_IFACE to $BRIDGE..."
ip link set $ETH_IFACE master $BRIDGE
ip link set $TAP_IFACE master $BRIDGE

echo "Bringing up $ETH_IFACE and $TAP_IFACE..."
ip link set $ETH_IFACE up
ip link set $TAP_IFACE up

echo "Assigning IP address to $BRIDGE..."
ip addr flush dev $ETH_IFACE
ip addr add $IP_ADDR dev $BRIDGE

echo "Setting up default gateway..."
ip route add default via $GATEWAY dev $BRIDGE

echo "Bridge setup complete. Current configuration:"
ip addr show $BRIDGE
bridge link show

If you have solutions that don't include a bridge I'm glad to hear them too :) The program I want to run is the lwIP Stack.