~$ lspci -nn 00:00.0 Host bridge : Intel Corporation 2nd Generation Core Processor Family DRAM Controller [8086:0104] (rev 09) 00:02.0 VGA compatible controller : Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) 00:16.0 Communication controller : Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 [8086:1c3a] (rev 04) 00:16.3 Serial controller : Intel Corporation 6 Series/C200 Series Chipset Family KT Controller [8086:1c3d] (rev 04) 00:19.0 Ethernet controller : Intel Corporation 82579LM Gigabit Network Connection [8086:1502] (rev 04) 00:1a.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 [8086:1c2d] (rev 04) 00:1b.0 Audio device : Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller [8086:1c20] (rev 04) 00:1c.0 PCI bridge : Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 [8086:1c10] (rev b4) 00:1c.1 PCI bridge : Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 [8086:1c12] (rev b4) 00:1c.3 PCI bridge : Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 [8086:1c16] (rev b4) 00:1c.4 PCI bridge : Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 5 [8086:1c18] (rev b4) 00:1d.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 [8086:1c26] (rev 04) 00:1f.0 ISA bridge : Intel Corporation QM67 Express Chipset Family LPC Controller [8086:1c4f] (rev 04) 00:1f.2 SATA controller : Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller [8086:1c03] (rev 04) 00:1f.3 SMBus [0c05]: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller [8086:1c22] (rev 04) 03:00.0 Network controller : Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] [8086:0085] (rev 34) 0d:00.0 System peripheral : Ricoh Co Ltd PCIe SDXC/MMC Host Controller [1180:e823] (rev 07) As [he was saying](https://unix.stackexchange.com/questions/645901/having-issue-with-debian-installation#comment1210259_645901) . I was following [the Wiki](https://wiki.debian.org/iwlwifi) . root@debian:/home/istiak# apt update && apt install firmware-iwlwifi Hit:1 http://security.debian.org/debian-security buster/updates InRelease Hit:2 http://deb.debian.org/debian buster InRelease Hit:3 http://deb.debian.org/debian buster-updates InRelease Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date. Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package firmware-iwlwifi root@debian:/home/istiak# modprobe -r iwlwifi ; modprobe iwlwifi bash: modprobe: command not found bash: modprobe: command not found When I try to run iwconfig or ifconfig I get that command not found. How can I install wifi driver? I have installed(iwlwifi-6000g2a-ucode-18.168.6.1.tgz) from [here](https://www.intel.com/content/www/us/en/support/articles/000005511/wireless.html) . When I extracted I got it(iwlwifi-6000g2a-6.ucode). What I have to do with it? Output of /usr/sbin/modprobe --version : kmod version 26 +XZ -ZLIB +OPENSSL -EXPERIMENTAL iwconfig : root@debian:~# /sbin/iwconfig enp0s25 no wireless extensions. wwp0s29u1u4 no wireless extensions. wlp3s0 IEEE 802.11 ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=0 dBm Retry short limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:off lo no wireless extensions. lspci -knn | grep -i net -A3 : istiak@debian:~$ lspci -knn | grep -i net -A3 00:19.0 Ethernet controller : Intel Corporation 82579LM Gigabit Network Connection [8086:1502] (rev 04) Subsystem: Lenovo 82579LM Gigabit Network Connection (Lewisville) (ThinkPad T520) [17aa:21ce] Kernel driver in use: e1000e Kernel modules: e1000e 00:1a.0 USB controller [0c03]: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 [8086:1c2d] (rev 04) -- 03:00.0 Network controller : Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] [8086:0085] (rev 34) Subsystem: Intel Corporation Centrino Advanced-N 6205 AGN [8086:1311] Kernel driver in use: iwlwifi Kernel modules: iwlwifi

I have a connection via VPN with my work. I know that internet connection (for example to 8.8.8.8) goes through my work network (only when I am connected to VPN). How to configure ip tables to force that connections to internet (for example 8.8.8.8) avoid work network ? Using @Julie help in comments I did managed to discover some options: " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy"> Nevertheless, after checking 'Use this connection only for resources...' I can't ping machines in VPN network. Can you tell me how should I deal with it ? I guess that I should click 'Add' and set: Address = address of some machine in VPN Netmask = I can get it from ifconfig (in VPN interface) Gateway - as in case of netmask Metri - I have no idea ? Am I right ?

On both the live image of Trisquel in a virtual machine:

$ sudo ifconfig up ens3
ens3: Host name lookup failure
ifconfig '--help' gives usage information

Here is my interfaces file: auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp auto eth0:0 iface eth0:0 inet static address 10.20.8.231 netmask 255.255.255.0 gateway 10.20.8.1 up /sbin/route add 1.2.3.4 gw 10.20.8.1 down /sbin/route del 1.2.3.4 gw 10.20.8.1 From the multiple examples I have found online this should add routes when eth0:0 comes up but for some reason I can't get it to work. When I try to bring up the interface with ifup eth0:0 I get: RTNETLINK answers: File exists Failed to bring up eth0:0. Then, ifconfig shows eth0:0 is up but route -n does not show the new route. In fact it shows the exact same routes I had before. Nothing changed. Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.20.8.1 0.0.0.0 UG 0 0 0 eth0 10.20.8.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 This config is to be used on remote systems that can only be accessed via SSH. The whole idea is to keep eth0 set to dhcp as a backup when the site's network is changed (happened twice already) rendering the static ip unaccessible. The problem with this is that SSH (used by built in processes) uses the default route via eth0 and that doesn't work as the firewall (not managed by us) has been set to allow ssh only for the static IP on eth0:0. Note: In the example above 1.2.3.4 represents our ssh server and I am trying to route traffic via eth0:0 for that single host but after testing I may want to set the default route to use eth0:0 instead, but I also tried that and it failed the same way. I was using this line: up route add -net 0.0.0.0 netmask 0.0.0.0 gw 10.20.8.1
**Thank you for your assistance.**

I've created a new LXC on debian jessie, but it doesn't have an ipv4 address. When I connect to my LXC and do ifconfig: eth0 Link encap:Ethernet HWaddr blabla inet6 addr: blabla/64 Scope:Global inet6 addr: blabla/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:81 errors:0 dropped:0 overruns:0 frame:0 TX packets:48 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:10368 (10.1 KiB) TX bytes:9480 (9.2 KiB) 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: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) As you can see, I have no inet addr in the eth0. I've tried to restart the networking service, but nothing has changed. How can I get an address? I even tried: lxc test stop lxc network attach lxdbr0 test eth0 eth0 lxc config device set test eth0 ipv4.address 10.99.10.42 lxc start test But nothing Thanks

I have two Asix USB to ethernet adapters. The FreeBSD determines those as ue1 and ue2 adapters. The problem is, that on reboot, sometimes the interface ue1 become ue2 and viceversa, which pretty much screws my network configuration. The both adapters have the very similar MAC, and might be the issue when system tries to recognize it. On the Linux systems, I previously sorted this out by setting static udev rules by adapters mac address. How I can achieve the similar in Freebsd? I know it is related to devd but I'm not sure how to manage it, so the adapters get 'static' name. usbconfig ugen0.1: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA) ugen0.2: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (2mA) ugen0.3: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (2mA) ugen0.4: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (248mA) ugen0.5: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (248mA) usbconfig -d ugen0.5 dump_device_desc ugen0.5: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (248mA) bLength = 0x0012 bDescriptorType = 0x0001 bcdUSB = 0x0210 bDeviceClass = 0x00ff bDeviceSubClass = 0x00ff bDeviceProtocol = 0x0000 bMaxPacketSize0 = 0x0040 idVendor = 0x0b95 idProduct = 0x1790 bcdDevice = 0x0100 iManufacturer = 0x0001 iProduct = 0x0002 iSerialNumber = 0x0003 bNumConfigurations = 0x0001 ugen0.4: at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (248mA) bLength = 0x0012 bDescriptorType = 0x0001 bcdUSB = 0x0210 bDeviceClass = 0x00ff bDeviceSubClass = 0x00ff bDeviceProtocol = 0x0000 bMaxPacketSize0 = 0x0040 idVendor = 0x0b95 idProduct = 0x1790 bcdDevice = 0x0100 iManufacturer = 0x0001 iProduct = 0x0002 iSerialNumber = 0x0003 bNumConfigurations = 0x0001

I installed just fine i attached the cloudlinux minimal iso file to my VPS and booted it from said file during the install it picked up the network just fine and once i rebooted the server it worked as soon as i installed cpanel and rebooted the VPS it broke and renamed eth0 to ens3 and i cannot figure out how to get it to stay as eth0 i can do ifconfig ens3 down then ip link set ens3 name eth0 followed by ifconfig eth0 up That makes it to where all 20 ip's are visible and can be pinged the weird thing is when i used ifup eth0 it kept saying nexthop has invalid gateway and it wouldn't work as soon as i used ifconfig eth0 up it worked i need it to stay as eth0 any help is appreciated thanks.

At some point, in some teaching material (from Linux Foundation) on Linux that I came across, the following is mentioned: > ip command is more versatile and more efficient than ifconfig because it uses **netlink** sockets rather than **ioctl** system calls. Can anyone elaborate a bit on this because I cannot understand what's going on under the hood? P.S. I am aware of this topic on those tools but it does not address this specific difference on how they operate

This tunnel won't remove. root@solaris10:~# ifconfig ip.6to4tun0 down ifconfig: setifflags: SIOCGLIFFLAGS: ip.6to4tun0: no such interface root@solaris10:~# ifconfig ip.6to4tun0 unplumb ifconfig: unplumb: SIOCGLIFFLAGS: ip.6to4tun0: no such interface The short answer will be "it din't exist!" but.. root@solaris10:~# ifconfig -a|ggrep -A 11 6to4 ip.6to4tun0: flags=2200041 mtu 65515 index 9 inet tunnel src 192.168.0.1 tunnel hop limit 60 inet6 fe80::203:baff:fe50:cbe6/128 The interface works ping 192.168.0.1 192.168.0.1 is alive ping -A inet6 fe80::203:baff:fe50:cbe6 fe80::203:baff:fe50:cbe6 is alive

This might be a bit stupid/naive question but I was at a conference event and after I connected to Free WiFi, I tried ifconfig in cmd of my cellphone via **Termux** and it did not work as follows:

> ifconfig
Warning: cannot open /proc/net/dev (Permission denied). Limited output.
lo: flags=73  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1  (UNSPEC)

wlan0: flags=4163  mtu 1500
        inet XX.XX.75.132  netmask 255.255.224.0  broadcast XX.XX.95.255
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)

before writing this post I thought used ipconfig but now I'm more curious why they closed/banned ifconfig command. Do they close this command when they configure the DHCP server to provide free internet access for the public or thesis configured somewhere else? and why? **Edit1:** as @Mircea Vutcovici proposed and commented - I installed getfacl via Termux on my cellphone and tried getfacl /proc/net/dev; it resulted in: > getfacl: /proc/net/dev: Permission denied - tried ls -lZd /proc/net/dev, it resulted in: > ls: cannot access '/proc/net/dev': Permission denied

Back when only ifconfig and route -n and cat /etc/resolv.conf were the only ways to check IP address / Mask / Gateway on a system -- was there a way to determine if these attributes were assigned via DHCP or statically? I know nmcli connection show will indicate if the ipv4.method is auto. And I know ip addr will list dynamic for DHCP assigned addresses. But outside of these two, and even _before_ these two packages existed, was it possible to tell? If so, how?

On the Busybox system I'm using, the output of busybox ifconfig -a includes a field for "Base address":

~ # busybox ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:D0:93:4D:AE:4F  
          inet addr:192.168.9.159  Bcast:192.168.9.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1 errors:0 dropped:0 overruns:0 frame:0
          TX packets:140 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:60 (60.0 B)  TX bytes:7136 (6.9 KiB)
          Base address:0xd000 

eth1      Link encap:Ethernet  HWaddr 00:D0:93:4D:AE:50  
          inet addr:192.168.9.160  Bcast:192.168.9.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:20 errors:0 dropped:0 overruns:0 frame:0
          TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1826 (1.7 KiB)  TX bytes:1678 (1.6 KiB)
          Base address:0x1000 

eth2      Link encap:Ethernet  HWaddr 00:D0:93:4D:AE:51  
          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)
          Base address:0xd000

I have been unable to find any information on what this represents, despite extensive searching. Can someone tell me what it is, since it's clearly considered important and relevant enough to include in ifconfig output?

I've just installed CentOS7 as a virtual machine on my mac (osx10.9.3 + virtualbox) .Running ifconfig returns command not found. Also running sudo /sbin/ifconfig returns commmand not found. I am root. The output of echo $PATH is as below. /usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/robbert/.local/bin:/home/robbert/bin Is my path normal? If not, how can I change it? Also, I don't have an internet connection on virtual machine yet, maybe that's a factor.

In a device with Debian BookWorm 12.5, I want to enable and disable a static IP using a Node application at runtime. The /etc/network/interfaces is the following : auto lo iface lo inet loopback ifconfig gives the following output : ~# ifconfig end0: flags=4163 mtu 1500 inet 192.168.109.176 netmask 255.255.255.0 broadcast 192.168.109.255 inet6 fe80::7376:77ae:719e:249f prefixlen 64 scopeid 0x20 ether f8:dc:7a:3e:8d:bb txqueuelen 1000 (Ethernet) RX packets 1155 bytes 392299 (383.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 519 bytes 84713 (82.7 KiB) 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 1 (Local Loopback) RX packets 344 bytes 23930 (23.3 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 344 bytes 23930 (23.3 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 Trying to turn-down the end0 interface, I get the following : ~# ifdown end0 ifdown: interface end0 not configured Then, I modify the /etc/network/interfaces as following : auto lo iface lo inet loopback auto end0 iface end0 inet static address 192.168.0.15 netmask 255.255.255.0 gateway 192.168.109.254 Trying to turn-up the interface with ifup end0, I get no error but the ifconfig output is the same as before. Trying again with ifup, I get the following : ~# ifup end0 ifup: interface end0 already configured and ifconfig gives the same output as before. I tried also to mess things up using ifconfig end0 down, service NetworkManager restart and service networking restart , but I continue to get undetermined behaviour, specially if I try to turn it down and up again when changing the interfaces file rolling back to dhcp configuration (i.e. without any reference to end0). What am i missing?

On a device with Debian 10, I want to make a permanent change to the IP via modifying ***/etc/network/interfaces*** . Hence, I modify it as follows : auto lo iface lo inet loopback auto eth0 #iface eth0 inet dhcp iface eth0 inet static address 192.168.109.11 netmask 255.255.255.0 gateway 192.168.109.254 and after that I perform the following : ifdown eth0 && ifup eth0 but at this point it returns the following error : root@var-som-mx6:~# ifdown eth0 && ifup eth0 --verbose ifdown: interface eth0 not configured ifup: configuring interface eth0=eth0 (inet) /bin/run-parts --exit-on-error --verbose /etc/network/if-pre-up.d run-parts: executing /etc/network/if-pre-up.d/hostapd run-parts: executing /etc/network/if-pre-up.d/wpasupplicant /sbin/ip addr add 192.168.109.12/255.255.255.0 broadcast 192.168.109.255 dev eth0 label eth0 /sbin/ip link set dev eth0 up /sbin/ip route add default via 192.168.109.254 dev eth0 onlink RTNETLINK answers: Invalid argument ifup: failed to bring up eth0 ***ifconfig*** tells me the following : root@var-som-mx6:~# ifconfig eth0: flags=4163 mtu 1500 inet 192.168.109.11 netmask 255.255.255.0 broadcast 192.168.109.255 inet6 fe80::fadc:7aff:fe3e:8dbb prefixlen 64 scopeid 0x20 ether f8:dc:7a:3e:8d:bb txqueuelen 1000 (Ethernet) RX packets 35999 bytes 8217478 (7.8 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5137 bytes 1559379 (1.4 MiB) 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 1 (Local Loopback) RX packets 2837 bytes 258173 (252.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 2837 bytes 258173 (252.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 What am I doing wrong?

Some background: sometimes my wi-fi connection suddenly goes down so I type sudo ifconfig wlan0 and check for the word RUNNING. The corresponding line looks like: UP BROADCAST RUNNING MULTICAST [...] When the connection goes down there's no RUNNING setting; I can't connect to anything but the interface is still up. I'm thinking of writing a script to periodically check for the RUNNING state. To extract that string, using awk would be something like: sudo ifconfig wlan0 | awk '/RUNNING/ {print $3}'. Is there another way such as checking the filesystem instead of parsing ifconfig's output? I'm using Debian Wheezy. Thanks. --- **More information:** OK, just did some research and cleared up some conceptual confusion. The UP and RUNNING flags are different. The first means the interface "is currently initialized" , i.e. "the system allocated the resources for the interface" --it doesn't say anything about packet transmission. The RUNNING flag actually indicates that packets are being sent and received. Apparently this flag disappears if e.g. the ethernet cable is unplugged. https://docs.oracle.com/cd/E19253-01/816-4554/ipconfig-141/index.html https://stackoverflow.com/questions/11679514/what-is-the-difference-between-iff-up-and-iff-running I don't know what is going on with my (or any) wireless connection, but the result is the same: the interface remains up (the wi-fi led light remains on in my laptop) while the connection is completely lost.

**Set up/configuration:** I have a RHEL 8 server, running Asterisk 15.x, that has 2 NICs. NMCLI is used for networking NIC0 (eno5np0) is on the trusted network and is configured as a static IPv4 and NIC1 (ens1f0) is on the untrusted side as a DHCP IPv4. Both are UP,BROADCAST,RUNNING,MULTICAST NIC0 is where I access the server from, is an internal network and has an IP of 10.38.149.244/32 (GW is 10.38.149.241) NIC1 is supposed to allow access to the internet (for SIP calling) and has an IP of 10.0.0.91 (GW is 10.0.0.1) Firewall status - inactive(dead) SE Linux status - disabled Server #1 interface configs: TYPE=Ethernet DEVICE=eno5np0 UUID=77c33e7a-7dba-4785-b749-dc0883b46cef ONBOOT=yes IPADDR=10.38.149.244 NETMASK=255.255.255.240 GATEWAY=10.38.149.241 NM_CONTROLLED=yes BOOTPROTO=none DOMAIN=comcast.net DNS1=69.252.80.80 DNS2=69.252.81.81 DEFROUTE=yes USERCTL=no IPV4_FAILURE_FATAL=yes TYPE=Ethernet BOOTPROTO=dhcp NM_CONTROLLED=yes PEERDNS=no DEFROUTE=no NAME=ens1f0 UUID=249b95f0-d490-4402-b654-43695317d738 DEVICE=ens1f0 ONBOOT=yes PROXY_METHOD=none BROWSER_ONLY=no IPV4_FAILURE_FATAL=no IPV6_DISABLED=yes IPV6INIT=no IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no **Kernel IP routing table:** | Destination | Gateway | Genmask | Flags | Metric | Ref | Use | Iface | | :----------- | :------- | :------- | :----- | :------ | :--- | :--- | :------| | 0.0.0.0 | 10.38.149.241 | 0.0.0.0 | UG | 100 | 0 | 0 | eno5np0 | | 10.0.0.0 | 0.0.0.0 | 255.255.255.0 | U | 101 | 0 | 0 | ens1f0 | | 10.38.149.240 | 0.0.0.0 | 255.255.255.240 | U | 100 | 0 | 0 | eno5np0 | I do not have any nft tables/IP tables configured I am SSH'd to the 10.38.149.244 interface (NIC0, aka eno5np0), have sudo access I run the following command for NIC0: sudo traceroute -i eno5np0 8.8.8.8 and get a nice, completed trace to 8.8.8.8 I run the following command for NIC1: sudo traceroute -i ens1f0 8.8.8.8 and it times out, no packets received I cannot ping/traceroute to any ip address through NIC1 (sudo ping -I and sudo traceroute -i) except 10.0.0.1, which is the gateway. It is almost like if it isn't the gateway the packets are not making it back into the server for processing? **Issue/Problem** So, after trying both ping and traceroute and not receiving a response, I opened a second SSH session to the server and did a tcpdump while running a ping to 8.8.8.8 over the NIC1 interface in my first SSH session: **TCP Dump** sudo tcpdump -vv --interface ens1f0 -c 10 dropped privs to tcpdump tcpdump: listening on ens1f0, link-type EN10MB (Ethernet), capture size 262144 bytes 15:21:09.450739 IP6 (flowlabel 0x9b9b7, hlim 255, next-header ICMPv6 (58) payload length: 120) fe80::1256:11ff:fe86:6e92 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 120 hop limit 64, Flags [managed, other stateful], pref medium, router lifetime 180s, reachable time 0ms, retrans timer 0ms rdnss option (25), length 40 (5): lifetime 180s, addr: device1.inetprovider.net addr: device2.inetprovider.net 0x0000: 0000 0000 00b4 2001 0558 feed 0000 0000 0x0010: 0000 0000 0001 2001 0558 feed 0000 0000 0x0020: 0000 0000 0002 prefix info option (3), length 32 (4): 2601:0:200:80::/64, Flags [onlink, auto], valid time 300s, pref. time 300s 0x0000: 40c0 0000 012c 0000 012c 0000 0000 2601 0x0010: 0000 0200 0080 0000 0000 0000 0000 route info option (24), length 24 (3): ::/0, pref=medium, lifetime=180s 0x0000: 0000 0000 00b4 0000 0000 0000 0000 0000 0x0010: 0000 0000 0000 source link-address option (1), length 8 (1): 10:56:11:86:6e:92 0x0000: 1056 1186 6e92 15:21:10.415419 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has dns.google tell 10.0.0.91, length 28 15:21:11.439570 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has dns.google tell 10.0.0.91, length 28 15:21:12.453262 IP6 (flowlabel 0x9b9b7, hlim 255, next-header ICMPv6 (58) payload length: 120) fe80::1256:11ff:fe86:6e92 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 120 hop limit 64, Flags [managed, other stateful], pref medium, router lifetime 180s, reachable time 0ms, retrans timer 0ms rdnss option (25), length 40 (5): lifetime 180s, addr: device1.inetprovider.net addr: device2.inetprovider.net 0x0000: 0000 0000 00b4 2001 0558 feed 0000 0000 0x0010: 0000 0000 0001 2001 0558 feed 0000 0000 0x0020: 0000 0000 0002 prefix info option (3), length 32 (4): 2601:0:200:80::/64, Flags [onlink, auto], valid time 300s, pref. time 300s 0x0000: 40c0 0000 012c 0000 012c 0000 0000 2601 0x0010: 0000 0200 0080 0000 0000 0000 0000 route info option (24), length 24 (3): ::/0, pref=medium, lifetime=180s 0x0000: 0000 0000 00b4 0000 0000 0000 0000 0000 0x0010: 0000 0000 0000 source link-address option (1), length 8 (1): 10:56:11:86:6e:92 0x0000: 1056 1186 6e92 15:21:12.463417 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has dns.google tell 10.0.0.91, length 28 15:21:13.487416 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has dns.google tell 10.0.0.91, length 28 15:21:13.546246 IP (tos 0x0, ttl 4, id 8382, offset 0, flags [DF], proto UDP (17), length 219) 169.254.100.1.50760 > 239.255.255.250.ssdp: [udp sum ok] UDP, length 191 15:21:13.546273 IP (tos 0x0, ttl 4, id 8383, offset 0, flags [DF], proto UDP (17), length 223) 169.254.100.1.50760 > 239.255.255.250.ssdp: [udp sum ok] UDP, length 195 15:21:13.546320 IP (tos 0x0, ttl 4, id 8384, offset 0, flags [DF], proto UDP (17), length 227) 169.254.100.1.50760 > 239.255.255.250.ssdp: [udp sum ok] UDP, length 199 15:21:13.546419 IP (tos 0x0, ttl 4, id 8385, offset 0, flags [DF], proto UDP (17), length 220) 169.254.100.1.50759 > 239.255.255.250.ssdp: [udp sum ok] UDP, length 192 10 packets captured 10 packets received by filter 0 packets dropped by kernel I am not understanding why, if the server is doing an ARP request, am I not getting a response? Is the issue on my server not knowing how to respond back to NIC0 with my ping request (where I am SSH'd into)? Is it the gateway being misconfigured? Do I need a NFT table/IP Table configured? I am familiar with how to do this in RHEL 6.x, but not in RHEL 8 (configuration using IP route and IP tables was simpler I think?) At the end of the day (for a broader picture) - I have Softphone clients to register to the Asterisk PBX on the internal/trusted network coming in over NIC0 (which works). They need to make phone calls to endpoints on the Internet, but only over NIC1 - and right now I cannot even ping to any location on the internet over the NIC1 interface. Any help/guidance would be very much appreciated at this point - I am lost and desperate. **Edit/additional clarification:** I have a RHEL 6.x server, with exact same physical connections and NICs that this does work on. I have tried to use the iptable and routing table from this Server #2 on Server #1 above and it will not work (I get booted when I turn the interface back up, and have to reboot the device to clear out any unsaved changes before I can get back in) I did use the iptables to nft translate function just as an FYI. I have plugged my Server #1 NIC1 into the known good modem/internet access port that Server #2 is using and still no change. Server #2 interface configs: DEVICE=eth0 BOOTPROTO=none NM_CONTROLLED=yes ONBOOT=yes TYPE=Ethernet UUID="da71293d-4351-481e-a794-bc5850e29391" IPADDR=10.38.149.243 DNS1=10.168.241.223 DOMAIN=comcast.net DEFROUTE=no IPV4_FAILURE_FATAL=yes IPV6INIT=no NAME="System eth0" #HWADDR=00:1C:23:CF:BC:E3 HWADDR=00:1c:23:cf:bc:e3 NETMASK=255.255.255.240 USERCTL=no PEERDNS=yes GATEWAY=10.38.149.241 DEVICE=eth1 BOOTPROTO=dhcp HWADDR=00:1c:23:cf:bc:e5 NM_CONTROLLED=yes ONBOOT=yes DEFROUTE=yes TYPE=Ethernet UUID="78bc69cb-80ca-41d1-af9c-66703eb952d5" USERCTL=no PEERDNS=yes IPV6INIT=no **Kernel Routing Table on Server #2** | Destination | Gateway | Genmask | Flags | Metric | Ref | Use | Iface | | :----------- | :------- | :------- | :----- | :------ | :--- | :--- | :------| | 0.0.0.0 | 10.0.0.1 | 255.255.255.255 | UGH | 0 | 0 | 0 | eth1 | | 10.38.149.240 | 0.0.0.0 | 255.255.255.240 | U | 0 | 0 | 0 | eth0 | | 10.0.0.0 | 0.0.0.0 | 255.255.255.0 | U | 0 | 0 | 0 | eth1 | | 10.0.0.0 | 10.38.149.241 | 255.0.0.0 | UG | 0 | 0 | 0 | eth0 | | 0.0.0.0 | 10.0.0.1 | 0.0.0.0 | UG | 0 | 0 | 0 | eth1 | iptables -L on Server #2 **Chain INPUT (policy ACCEPT)** | target | prot | opt | source | destination | status? | | :------| :----| :----| :-----| :-----------| :-------| | DROP | all | -- | c-67-164-235-175.devivce1.mi.inetprovider.net | anywhere | | | DROP | all | -- | c-67-164-235-175.devivce1.mi.inetprovider.net | anywhere | | | ACCEPT | all | -- | anywhere | anywhere | | | ACCEPT | all | -- | anywhere | anywhere | state RELATED,ESTABLISHED | | ACCEPT | tcp | -- | anywhere | anywhere | tcp dpt:ssh | | ACCEPT | udp | -- | anywhere | anywhere | udp dpt:sip | | ACCEPT | udp | -- | anywhere | anywhere | udp dpts:ndmp:dnp | | DROP | all | -- | 106.0.0.0/8 | anywhere | | | DROP | all | -- | 106.0.0.0/8 | anywhere | | | DROP | all | -- | host-87-0-0-0.retail.blockeddomain.notus/8 | anywhere | | | DROP | all | -- | 113.0.0.0/8 | anywhere | | | DROP | all | -- | 117.0.0.0/8 | anywhere | | | DROP | all | -- | p5b000000.dip0.blockeddomain.notus/8 | anywhere | | **Chain FORWARD (policy ACCEPT)** | target | prot | opt | source | destination | | :------| :----| :---| :------| :-----------| | ACCEPT | all | -- | anywhere | anywhere | **Chain OUTPUT (policy ACCEPT)** | target | prot | opt | source | destination | | :------| :----| :---| :------| :-----------|

Running Ubuntu 22.04.3 LTS on top of WSL2 Output of ifconfig: eth0: flags=4163 mtu 1492 inet 172.28.193.11 netmask 255.255.240.0 broadcast 172.28.207.255 inet6 fe80::215:5dff:fe3e:7ffa prefixlen 64 scopeid 0x20 ether 00:15:5d:3e:7f:fa txqueuelen 1000 (Ethernet) RX packets 1402 bytes 590609 (590.6 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 163 bytes 52446 (52.4 KB) 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 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 Output of ipconfig /all from PowerShell (pardon my machine's French): Configuration IP de Windows Nom de l’hôte . . . . . . . . . . : Zenbook-OZ Suffixe DNS principal . . . . . . : Type de noeud. . . . . . . . . . : Hybride Routage IP activé . . . . . . . . : Non Proxy WINS activé . . . . . . . . : Non Liste de recherche du suffixe DNS.: Speedport_W_724V_01011603_07_008 Carte réseau sans fil Connexion au réseau local* 1 : Statut du média. . . . . . . . . . . . : Média déconnecté Suffixe DNS propre à la connexion. . . : Description. . . . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter Adresse physique . . . . . . . . . . . : 3E-55-76-BE-66-95 DHCP activé. . . . . . . . . . . . . . : Oui Configuration automatique activée. . . : Oui Carte réseau sans fil Connexion au réseau local* 2 : Statut du média. . . . . . . . . . . . : Média déconnecté Suffixe DNS propre à la connexion. . . : Description. . . . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter #2 Adresse physique . . . . . . . . . . . : 3E-55-76-BE-76-85 DHCP activé. . . . . . . . . . . . . . : Oui Configuration automatique activée. . . : Oui Carte réseau sans fil Wi-Fi : Suffixe DNS propre à la connexion. . . : Speedport_W_724V_01011603_07_008 Description. . . . . . . . . . . . . . : MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz Wireless LAN Card Adresse physique . . . . . . . . . . . : 3C-55-76-BE-46-B5 DHCP activé. . . . . . . . . . . . . . : Oui Configuration automatique activée. . . : Oui Adresse IPv6. . . . . . . . . . . . . .: 2003:c5:c715:bad9:aa0e:5e09:f399:6903(préféré) Adresse IPv6 temporaire . . . . . . . .: 2003:c5:c715:bad9:fc98:b63c:31e6:1374(préféré) Adresse IPv6. . . . . . . . . . . . . .: 2003:c5:c715:badb:904b:d90b:7543:f858(déprécié) Adresse IPv6 de liaison locale. . . . .: fe80::f215:b016:e094:6711%13(préféré) Adresse IPv4. . . . . . . . . . . . . .: 192.168.2.106(préféré) Masque de sous-réseau. . . . . . . . . : 255.255.255.0 Bail obtenu. . . . . . . . . . . . . . : mercredi 13 mars 2024 01:52:12 Bail expirant. . . . . . . . . . . . . : jeudi 4 avril 2024 00:38:51 Passerelle par défaut. . . . . . . . . : fe80::1%13 192.168.2.1 Serveur DHCP . . . . . . . . . . . . . : 192.168.2.1 IAID DHCPv6 . . . . . . . . . . . : 121394550 DUID de client DHCPv6. . . . . . . . : 00-01-00-01-2C-2A-D6-E9-00-4C-E0-86-43-54 Serveurs DNS. . . . . . . . . . . . . : fe80::1%13 192.168.2.1 NetBIOS sur Tcpip. . . . . . . . . . . : Activé Carte Ethernet Connexion réseau Bluetooth : Statut du média. . . . . . . . . . . . : Média déconnecté Suffixe DNS propre à la connexion. . . : Description. . . . . . . . . . . . . . : Bluetooth Device (Personal Area Network) Adresse physique . . . . . . . . . . . : 3C-55-76-BE-46-B6 DHCP activé. . . . . . . . . . . . . . : Oui Configuration automatique activée. . . : Oui Carte Ethernet vEthernet (WSL (Hyper-V firewall)) : Suffixe DNS propre à la connexion. . . : Description. . . . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter Adresse physique . . . . . . . . . . . : 00-15-5D-AE-85-70 DHCP activé. . . . . . . . . . . . . . : Non Configuration automatique activée. . . : Oui Adresse IPv6 de liaison locale. . . . .: fe80::5516:60d0:65b2:eb67%35(préféré) Adresse IPv4. . . . . . . . . . . . . .: 172.28.192.1(préféré) Masque de sous-réseau. . . . . . . . . : 255.255.240.0 Passerelle par défaut. . . . . . . . . : IAID DHCPv6 . . . . . . . . . . . : 587208029 DUID de client DHCPv6. . . . . . . . : 00-01-00-01-2C-2A-D6-E9-00-4C-E0-86-43-54 NetBIOS sur Tcpip. . . . . . . . . . . : Activé **My question:** I don't understand where the IP address 172.28.193.11 (assigned to eth0 in the output ifconfig) comes from. The MAC address 00:15:5d:3e:7f:fa associated to eth0 in ifconfig does not appear anywhere in the output of ipconfig /all on PowerShell. To what network interface does the MAC address 00:15:5d:3e:7f:fa correspond?

I have a RHEL/CentOS7 installation with some unused network ports. NetworkManager is not in use on this system, only the legacy "ifupdown" network scripts. I would like to "disable" the unused network ports to prevent accidental use, and I have considered simply deleting the corresponding /etc/sysconfig/network-scripts/ifcfg-* files. I know that the interface can then no longer be activated manually via ifup, but I want to be sure that there is no "default" behavior which would allow a (non-root) user to plug in a network cable and then get these interfaces working anyway. **So the question is:** Can a network interface be activated by a non-root user (e.g. due to some automatic fall-back behavior) under legacy network scripts if there is no ifcfg- file corresponding to that interface? (Alternative formulation: What is the default behavior of a network interface if there is not ifcfg- file for it?)

In Red Hat Enterprise Linux (RHEL) 8, if someone does ifconfig eth0 hw ether abcd12341234, *all I know is ifconfig and ip -a*, so then is there a way to reliably get the real MAC address of that eth0 interface and if so how? ... other than for example rebooting to a Linux live CD coming from a reliable source to be sure the MAC address of the interface hasn't been changed.