I modified /etc/resolv.conf to configure DNS for my VPN. Now I would like to modify it again but I can't. The operation is not permitted even if I use   sudo nano /etc/resolv.conf   I tried to start in recovery mode but I have the same problem. How can I restore this file?
76058
Is /etc/resolv.conf useless in  (Precise Pangolin)?  I see that the DNS server information is stored in  now. The nmcli command line tool can list that for you.  If I want to add one more  server, will adding it to /etc/resolv.conf by using the resolvconf package help?
8372
QUESTION:  How might I be able to specifically change the Mac Address of the enp3s0 and wlp2s0 interfaces through the /etc/network/interfaces file? What code would I have to include inside? I have been trying for some time now without success sadly enough.    ELABORATING:  So I found this great article online explaining how to change a Mac Address permanently through the /etc/network/interfaces file on my Ubuntu.  In the article, it says:      On Debian, Ubuntu, and similar systems, place the following in the   appropriate section of /etc/network/interfaces (within an iface   stanza, e.g., right after the gateway line) so that the MAC address is   set when the network device is started:      hwaddress ether 02:01:02:03:04:08   Source:   Now when I use the following code:  cat /etc/network/interfaces   I get the following output  # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback   And when I do ifconfig on my ubuntu, I get back 3 different interfaces:   enp3s0 lo wlp2s0   I would like to change the mac address of all of my interfaces (enp3s0, wlp2s0) (lo is loopback so no need there), but I am unfamiliar with the commands in the /etc/network/interfaces file. I have been looking at tutorials online though I can't seem to get stuff right, and my computer even started acting very strangely a few times afterwards.
87560
under /etc/sysconfig/network-scripts ,  we have network configuration files as   ifcfg-conf1 ifcfg-conf2  . . .   is it possible to change all parameters - PEERDNS to no , if value is yes  expected results on all ifcfg-xxxx files  PEERDNS=no    wrong  ifcfg-xxxx files configuration   PEERDNS=yes   the reason for this change is because /etc/resolve.conf changed after reboot so we need to change all PEERDNS variables to no
60517
sudo: unable to resolve host   I think I need to edit the /etc/hosts file to make an entry for 127.0.1.1 PC name.  But how can I do that if I can't access sudo? It seems to have gone since I updated to 13.10.  I have tried nano, which still doesn't work.
123735
When I use the sudo command I get an error message.  sudo: /etc/sudoers is world writable sudo: no valid sudoers sources found, quitting sudo: unable to initialize policy plugin   If I try to use chmod on sudoers I get the message "Operation not permitted". Can someone help me fix things so sudo works again?
111797
I'd like to make some changes to my networking configuration by editing my /etc/network/interfaces file. What's the cleanest way to make changes to this file and have them take effect, without having to reboot? Typically, I've been doing:   Edit the file service networking restart   But I have the impression that this isn't the "right" way to make these kinds of changes.
32338
After updating /etc/network/interfaces with something very similar to below, how do I get /etc/resolv.conf to update?  I tried (as root) resolver -u, service networking restart but they didn't work. I also fixed the symlink for resolv.conf and tried resolver -u again. Finally in frustration I rebooted, which did fix the problem by rebuilding /etc/resolv.conf.  Ubuntu 12.04, 64bit server, all the latest patches installed.  Example /etc/network/interfaces:  iface eth0 inet static     address 192.168.3.3     netmask 255.255.255.0     gateway 192.168.3.1     dns-search example.com     dns-nameservers 192.168.3.45 192.168.8.10
37272
I'll try to explain this as best I can...  I'm on ubuntu 13.04, and I am running a local BIND instance at 127.0.0.1 for access to basic wild-card DNS for development (i.e. "*.dev == 127.0.0.1" - yes, I know, don't create fake tlds, etc. This is entirely local to my machine, though).  I also have clients who have their own DNS servers set up through a VPN (at 192.168.140.111 or something similar).  My problem is that if my resolv.conf has their DNS server listed first, I can't access my *.dev, and if I have my DNS server listed first, I can't access their *.vpn records.  Currently, this is my resolv.conf:  # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN nameserver 192.168.140.111 search ns1.vpn nameserver 127.0.0.1 nameserver 127.0.1.1 search fritz.box   The first three lines of the config are in /etc/resolvconf/resolv.conf.d/head, so they'll survive through a resolvconf -u.  Essentially what I want to know is this: is there a way for me to set this up so *.dev goes to my dns server, and *.vpn goes to theirs, (and everything else goes off to my ISP).
60767
Does anyone know an easy practical way to remove configuration blocks. I have a file in the format:  lease {   interface "eth0";   ... } lease {   interface "wlan3";   fixed-address 192.168.0.108;   option subnet-mask 255.255.255.0;   ... }   I want to remove the configuration block for interface "wlan3";.   I started trying to write a custom grep function but it was getting complex quickly.  This seems like something that might be a common problem. Does anyone have a convenient solution for dealing with configuration files of this format?
36763
I have messed up my sudoers file and I want to change the permission on it.   When I login in recovery mode, I cannot run the command chmod as it is read-only option.  I tried mount -o remount,rw / in recovery mode. Didn't work for me:  Err : Ext4-fs remount. Opts errors=remount-ro    How can I boot into recovery mode and with read-write option?
26615
I needed to edit a .config file (which I know for a fact is not creating these problems, just to clear that up) and it wouldn't let me save it, so I took ownership of /etc and all contents with the command chown -hR username /etc and that let me edit the .config file but now whenever I try to install any packages or use any sudo commands, it doesn't work  (I've checked for errors in the sudo file in sudoers.d and there was nothing wrong with that).   So how do I return it to the previous owner?
89682
I want to revert a file in /etc/ back to its originally-installed form. I have edited the file since it was installed. How can I revert this config file? Apt is smart enough not to overwrite edited config files, so how do I tell it that I want it to do so?  For argument's sake, let's say that I want to revert the file /etc/foo.conf from the package foo.
46460
I recently tried to delete unoDNS from my laptop. A member of their team gave me some commands to input in a terminal. It looked like it changed the nameserver address back to 8.8.8.8. But after I restarted my laptop I cant connect to internet at all. I am using ubuntu 14.04. Please help.
71514
With nmcli, I can modify VPN data like this:  nmcli con modify myvpn vpn.data 'refuse-pap = yes, user = xxx'   So I'm wondering if I can set password this way as well?
93268
I was doing some experiment about resource-accessing. By mistake, I executed this command, $ sudo mv /etc/passwd /etc/passwd.bak Then I could not execute any command with privilege(eg. sudo mv /etc/passwd.bak /etc/passwd). When I shut the system down, I could not boot it any more. Afterwards, I restored the passwd file with a LiveCD.  Any other approaches could make it?
40684
According to  it appears to be simple. However, /etc/bind does not exist on the default installation of Ubuntu 12.04.3 LTS server.  So, without installing any further software, how can configure DNS and remove dnsmasq on ubuntu server? I am quite familiar with sudo &amp; nano.
100440
Not that it's a very good idea to change it, but for fun. According to  post, there are still some problems even after changing entries in /etc/passwd, /etc/shadow, and /etc/sudoers. Any suggestions?