I am trying to use ifdown command on my network interface (enp0s3), but it claims, that this interface is not known. When I try the same command with my loopback lo it works fine. What could be the problem ? My network-manager is sure off, only networking daemon is running.  lsb_release -d    Ubuntu 18.04.1 LTS  cat /etc/netplan/50-cloud.init.yami     You should probably know, it is on VM.
123631
Starting sometime around Ubuntu 18.04, the Ubuntu devs stopped using the classic /etc/init.d/networking and /etc/network/interfaces method of configuring the network and switched to some thing called . This has made a lot of people very angry and been widely regarded as a bad move. Is it possible to remove netplan and use the correct /etc/network/interfaces method for configuring the network?
124107
I'm having a really hard time configuring ubuntu 13.04 to have a static ip address. I have tried multiple solutions but everytime I reboot (can't do the network reset command because ubuntu freezes) I end up with no connection.  Here is what I get when i type ifconfig into the terminal:  eth0      Link encap:Ethernet  HWaddr 10:bf:48:bc:07:cb             inet addr:192.168.0.8  Bcast:192.168.0.255  Mask:255.255.255.0           inet6 addr: fe80::12bf:48ff:febc:7cb/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:1763067 errors:0 dropped:0 overruns:0 frame:0           TX packets:1024326 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:2284491220 (2.2 GB)  TX bytes:136809317 (136.8 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:1840 errors:0 dropped:0 overruns:0 frame:0           TX packets:1840 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:185688 (185.6 KB)  TX bytes:185688 (185.6 KB)   I have also tried this:  auto lo iface lo inet loopback auto eth0 iface eth0 inet static         address 192.168.0.160         netmask 255.255.255.0         broadcast 192.168.0.255         gateway 192.168.0.1         dns-nameservers 24.222.0.94         dns-nameservers 24.222.0.95   If anyone could help me it would be very much appreciated.
4064
I tried to use  sudo service networking restart   and  sudo /etc/init.d/network restart   but they both crash the window manager and I can no longer use my keyboard for input into X.  when I use the /etc/init.d/ method it complains saying that I should use the service utility  e.g. service networking restart   but it crashes just the same.  Is there a GUI method of restarting networking?
63334
I run Ubuntu 12.04 on an old iMac G3. Since the GUI is too resource heavy I have disabled the display manager (lightdm) and am currently running the computer in console mode. How do I establish a mobile broadband connection from the command line?  When I connect the modem it shows up as ttyUSB0 in the Network Manager device list:  $ nmcli dev DEVICE     TYPE              STATE         ttyUSB0    gsm               disconnected     eth0       802-3-ethernet    unavailable   I have also copied a working connection configuration file from another computer to /etc/NetworkManager/system-connections/Com\ Hem\ Default\ 1. Still, when I try to connect I get an "unknown connection" error:  $ nmcli con up id "Com Hem Default 1" Error: Unknown connection: Com Hem Default 1.   Any clues?
36750
I am trying to write a unit file for hostapd on Debian.   The hostapd daemon seems to need the interface for the associated Wifi interface to be up before it is run or else it SEGV's.   I've tried network-online.target, but still get the SEGV. I think this is because network-online.target only needs to see ANY interface up, and other interfaces comes up before the Wifi interface is ready enough for hostapd to work.    What is the best way to have a service wait for a specific interface to be up before starting?
76525
I've always used the ifcfg-eth0:1 alias files to create additional addresses. However, in , it states that:     As the ip command of the iproute package now supports assigning multiple address to the same interface it is no longer necessary to use this method of binding multiple addresses to the same interface.    Furthermore, numerous answers and comments on this site mention that ifconfig is deprecated and that "ip" should be used instead.  I'm fine using it for live changes, but how do I persist the changes across reboots without using the alias files?
79493
I want to find a list of all network services running on my system, including details of the port and services and the users. I know that I need to use netstat, ps and fuser. but I don't know how to write the command. Do I need to write a shell script to find all of them? or I can use in a line of commands? Thanks for your help.
121747
Compare Debian (left) and Ubuntu (right):  $ ifconfig                                 $ ifconfig bash: ifconfig: command not found          eth0     Link encap ... $ which ifconfig                           $ which ifconfig $                                          /sbin/ifconfig   Then as superuser:  # ifconfig                                 # ifconfig eth0      Link encap ...                   eth0     Link encap ... # which ifconfig                           # which ifconfig /sbin/ifconfig                             /sbin/ifconfig   Furthermore:  # ls -l /sbin/ifconfig                     # ls -l /sbin/ifconfig -rwxr-xr-x 1 root root 68360 ...           -rwxr-xr-x 1 root root 68040 ...   It seems to me the only reason I cannot run ifconfig without superpowers on Debian is that it's not in my path. When I use /sbin/ifconfig it does work.   Is there any reason I should not add /usr/local/sbin:/usr/sbin:/sbin to my path on Debian? This is a personal computer, I am the only human user.    Versions used (uname -a): Ubuntu:   Linux ubuntu 3.13.0-51-generic #84-Ubuntu SMP Wed Apr 15 12:08:34 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux   Debian:  Linux debian 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1+deb8u3 (2015-08-04) x86_64 GNU/Linux
75813
While looking to find the MAC Address of my computer as it appears to a wireless network, it was recommended that I run ifconfig.  Having executed that command in the Terminal, I noticed that, unlike my other machine, the connected network seemed to be listed as an Ethernet, even though the built in wireless card is the thing I am currently using to post this.  ifconfig output:  lewisgoddard@t42:~$ ifconfig eth0      Link encap:Ethernet  HWaddr 00:0d:60:7b:d2:18             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)  eth1      Link encap:Ethernet  HWaddr 00:0c:f1:53:55:c5             inet addr:192.168.1.10  Bcast:192.168.1.255  Mask:255.255.255.0           inet6 addr: fe80::20c:f1ff:fe53:55c5/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:716 errors:1 dropped:1 overruns:0 frame:0           TX packets:710 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:620786 (620.7 KB)  TX bytes:80480 (80.4 KB)           Interrupt:11 Base address:0xe000 Memory:c0210000-c0210fff   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:16436  Metric:1           RX packets:182 errors:0 dropped:0 overruns:0 frame:0           TX packets:182 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:19665 (19.6 KB)  TX bytes:19665 (19.6 KB)   Is it possible that Ubuntu is confused somehow?  If not, am I misinterpreting my results, and my MAC Address may not be 00:0c:f1:53:55:c5 ?
22976
I'm trying to find speed of network interface using file-descriptor. It's easy to do it for ethX, just calling cat /sys/class/net/eth0/speed. Unfortunately this method doesn't work with wireless interface. When I call /sys/class/net/wlan0/speed I get error: invalid argument.   So, do you know any /sys/class/net/eth0/speed like analog for wlan interface?
99585
Ex.: an sshd is configured to only listen on wlan0. So. Besides checking the sshd_config how can I check that a daemon is listening on what inerface? netstat can do it? how? (OS: openwrt or scientific linux or openbsd)  UPDATE:   I thought sshd could be limited to an interface... but no... (192.168.1.5 is on wlan0...)  # grep ^ListenAddress /etc/ssh/sshd_config  ListenAddress 192.168.1.5:22 #  # lsof -i -n -P COMMAND     PID USER   FD   TYPE  DEVICE SIZE/OFF NODE NAME sshd      23952 root    3u  IPv4 1718551      0t0  TCP 192.168.1.5:22 (LISTEN) # # ss -lp | grep -i ssh 0      128              192.168.1.5:ssh                           *:*        users:(("sshd",23952,3)) #  # netstat -lp | grep -i ssh tcp        0      0 a.lan:ssh                   *:*                         LISTEN      23952/sshd           #
67442
I've just installed a Fedora 19 on VMware workstation 9. The default network device is "ens33" instead of "eth0" on RHEL.  The reason I have to use "eth0" is that the license component of one of our products has be to be linked with "eth0".  There are some posts discussing about similar issues, most of which are for older OS. I haven't found one that exactly match my situation.
35897
What's the best approach towards determining if I have a rogue DHCP server inside my network?  I'm wondering how most admins approach these kinds of problems.  I found  through searching, and thought about trying it out.  Has anyone had experience with it? (I would like to know before taking the time to compile it and install).  Do you know any useful tools or best-practices towards finding rogue DHCP servers?
59312
I'm trying to set up apache2 server on Debian 9. I'm using an laptop with Ralink network-card, witch was able to use eth0, at Debian 8, with looks more familiar for me. Since I update my system to 9 my network interface has changed and looks something like this:  Iface      MTU    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg enp37s0   1500        0      0      0 0             0      0      0      0 BMU lo       65536      612      0      0 0           612      0      0      0 LRU wlo1      1500    36736      0      1 0         20492      0      0      0 BMRU   and  in the /etc/interfaces.d/setup file it's defined like:  auto lo iface lo inet loopback  auto eth0 iface eth0 inet dhcp   What is the enp37s0? And why am I connected to the router with wlo1, not eth0?   My routing table:  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 0.0.0.0         10.63.16.1      0.0.0.0         UG    600    0        0 wlo1 10.63.16.0      0.0.0.0         255.255.255.0   U     600    0        0 wlo1 169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 wlo1   Is that a proper configuration?
120011
I have Ubuntu 12.10 on which I installed virtual box on which I setup Centos 6.4 i386. On Ubuntu I have: 3.5.0-17-generic kernel running.  On virtual box I install Centos 6.4 and everything works fine, however when I boot into VM machine, there is only on loopback interface. Nothing else. I tried to manually add ifcfg-eth0 file but nothing happens. On VM settings I have added NAT and HostOnly interfaces but whenever I boot into Centos there is just lo interface. What should I do?
13217
Typing ifconfig on the command line gives me listings for several devices. I've seen at least the following ones:    lo0 gif0 stf0 en0 en1 en2 en3 p2p0 awdl0 bridge0   What specifically do each of them refer to? I know en0 is a wireless connection, en3 is a connection using a Thunderbolt-to-ethernet adapter, and en1 is an ordinary ethernet connection. What about the rest?
106062
I'm trying to configure a ubuntu server network. [Edit] My ifconfig: lo: flags=73&lt;UP,LOOPBACK,RUNNING&gt; mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10&lt;host&gt; loop txqueuelen 1000 (Loopback Local) RX packets 352 bytes 26160 (26.1KB) RX erors 0 dropped 0 overruns 0 frame 0 TX packets 352 bytes 26160 (26.1KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0  I edited the /etc/network/interfaces file and here is how it is: auto lo auto eth0 iface eth0 inet static address 192.168.15.141 netmask 255.255.255.0 gateway 192.168.15.1  I'm trying to restart the server and I'm using: sudo ifdown --exclude=lo -a &amp;&amp; sudo ifup --exclude=lo -a  This command is an answer from this link:  And I'm getting the following error: Cannot find device &quot;eth0&quot; Failed to bring up eth0.  I'm pretty lay in configuring a server, so I have no idea what's going on. Can someone help me please?