Disabling Network Manager in RHEL 6

Note: REHL7 is diffest from RHEL6 to the extent that it should be called a separate flavor of Linux (much like RHEL6 and Suse 10 are different flavours of linux), not an  upgrade to RHEL6. For dealing with Network Manager idiosyncrasies in RHEL7 see Disabling Network Manager in RHEL7

RHEL 6  configured to use Network Manager, even if we install server. Network Manager is a desktop component, which is semi-useless for rack mounted servers with static IP and cable connection (it can be useful for initial installation, when your switch is not yet configured; you can use instead wireless card  to configure server via wireless network or USB to Ethernet adapter which you can connect to desktop DHCP segment). 

Moreover Network Manager is essentially a DHCP beast and it overwrites /etc/resolv.conf if you configure static IP parameters (see Network Manager overwrites resolv.conf for details) on reboot.  That comes to very unpleasant surprise as servers are not rebooted often and at this point you do not expect this Trojan horse inside your environment ;-)

Functionally Network Manager replaces old /etc/init.d/network script, but its useful functionality is limited mainly to wireless networks and desktops/laptops which use DHCP. It typically causes allergy for sysadmins who get used to static IP stack assignments.  And overwriting /etc/resolv.conf is just one of several side effects.

How to Disable Network Manager completely

To disable Network Manager please follow instructions below.  First you need to disable it from init and shutdown the service:

chkconfig NetworkManager off
service NetworkManager stop

How to disable Network Manager for particular interfaces only

If you need wireless connection on your server, or connection that you need to control similarly, you might try to excluded some Ethernet interfaces from control of network manager. In this case you need

• To modify  the  /etc/sysconfig/network-scripts/ifcfg-eth0  file for interfaces you need to put outside control of Network Manager 
• To enable network service so that this interface was server by "old fashioned way".

In the  /etc/sysconfig/network-scripts/ifcfg-eth0 only one parameter matter: to disable NM you can put NM_CONTROLLED="no"

DEVICE="eth0"
NM_CONTROLLED="no"
ONBOOT="yes"
HWADDR=00:50:56:AB:50:90
TYPE=Ethernet
BOOTPROTO=none
IPADDR=10.12.36.89
PREFIX=22
GATEWAY=10.12.36.1
DNS1=10.12.5.20
DOMAIN="some.company.net"
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"

After restarting NeworkManager service verify that Network Manager is successfully disabled for eth1.

nmcli dev status

nmcli
Usage: nmcli [OPTIONS] OBJECT { COMMAND | help }

OPTIONS
  -t[erse]                                   terse output
  -p[retty]                                  pretty output
  -m[ode] tabular|multiline                  output mode
  -f[ields] |all|common   specify fields to output
  -e[scape] yes|no                           escape columns separators in values
  -v[ersion]                                 show program version
  -h[elp]                                    print this help

OBJECT
  nm          NetworkManager status
  con         NetworkManager connections
  dev         devices managed by NetworkManager

Enable network service so that particular interface (eth0 in our example) is activated by network service automatically upon boot.

Now it make sense that you can specify DNS server /etc/sysconfig/network-scripts/ifcfg-eth0  per interface.

Removing Network Manager completely from the OS

You can also remove NetworkManager completely. For example

rpm -qa | fgrep "Network" 

And based on result of the search delete RPMs involved.

rpm -e NetworkManager-0.8.1-66.el6.x86_64 NetworkManager-gnome-0.8.1-66.el6.x86_64

If you specified network parameters during install the  GATEWAY  info is duplicated in the /etc/sysconfig/network:

NETWORKING=yes
HOSTNAME=box89.some.company.net
GATEWAY=10.12.36.1

If you change gateway manually without using GUI applet you need to change it in all places.

NEWS CONTENTS

• 20210312 : How to Set a Static IP Address in CentOS Linux by an IP Address. Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . An IP ( Internet Protocol ) Address is a unique numerical representation of a computer on a network. Every computer connected to the Internet is identified by an IP Address. Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Today, we will learn how to set a static IP address on a local network in CentOS . Today, we will learn how to set a static IP address on a local network in CentOS . List Network Interface Name A computer can be connected to one or more network interfaces, for example to a WiFi device and a LAN device, which has different IP addresses for each interface. Run the following command to show the interface names. A computer can be connected to one or more network interfaces, for example to a WiFi device and a LAN device, which has different IP addresses for each interface. Run the following command to show the interface names. Run the following command to show the interface names. Run the following command to show the interface names.

  # ifconfig OR # ip addr 

  

  The interface ' enp0s3 ' is the LAN device connected to my computer and the IP Address is ' 10.0.2.15 '. The other interface ' lo ' ( Loopback ) which is nothing but the local network of the computer within itself. Thus my computer is only connected to one interface, ' enp0s3 '. The interface ' enp0s3 ' is the LAN device connected to my computer and the IP Address is ' 10.0.2.15 '. The other interface ' lo ' ( Loopback ) which is nothing but the local network of the computer within itself. Thus my computer is only connected to one interface, ' enp0s3 '. Configuring Static IP Address in CentOS Go to directory ' /etc/sysconfig/network-scripts ' and list the files; you should see a file corresponding to your network interface. Go to directory ' /etc/sysconfig/network-scripts ' and list the files; you should see a file corresponding to your network interface.

  $ cd /etc/sysconfig/network-scripts $ ls 

  

  Open the file 'ifcfg-enp0s3' using ' Open the file 'ifcfg-enp0s3' using ' Vim ' or any editor of your choice. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set.

  

  Save and exit the file. Restart the networking service with the following commands: Save and exit the file. Restart the networking service with the following commands:

  # nmcli networking off # nmcli networking on 

  Finally, run ' ifconfig ' again to verify if static IP has been set. Finally, run ' ifconfig ' again to verify if static IP has been set.

  # ifconfig 

  

  ( Mar 12, 2021 , www.linuxshelltips.com )
• 20190406 : IP Aliasing Assigning multiple IP addresses to single NIC - LinuxTechLab ( Apr 06, 2019 , linuxtechlab.com )
• 20190204 : How to disable NetworkManager on CentOS - RHEL 7 by admin ( Feb 04, 2019 , www.thegeekdiary.com )
• 20190130 : How to take back control of /etc/resolv.conf on Linux ( Jan 30, 2019 , www.ctrl.blog )
• 20190130 : Disabling Network Manager ( )
• 20170805 : Disabling NetworkManager on RHEL 7 ( Aug 01, 2017 , superuser.com )
• 20170802 : Issue with RHEL7 and disabling NetworkManager ( Aug 02, 2017 , serverfault.com )

Old News ;-)

[Mar 12, 2021] How to Set a Static IP Address in CentOS Linux by an IP Address. Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . An IP ( Internet Protocol ) Address is a unique numerical representation of a computer on a network. Every computer connected to the Internet is identified by an IP Address. Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Usually, IP addresses are dynamically assigned to a computer by a dedicated server called DHCP Server ( Dynamic Host Control Protocol ), and hence change from time to time as and when the connection is lost and reestablished. However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . However, there are scenarios where a static IP address is more preferable; Eg. In large corporations, where it removes the load of using DHCP for each computer in the organization. Today, we will learn how to set a static IP address on a local network in CentOS . Today, we will learn how to set a static IP address on a local network in CentOS . Today, we will learn how to set a static IP address on a local network in CentOS . List Network Interface Name A computer can be connected to one or more network interfaces, for example to a WiFi device and a LAN device, which has different IP addresses for each interface. Run the following command to show the interface names. A computer can be connected to one or more network interfaces, for example to a WiFi device and a LAN device, which has different IP addresses for each interface. Run the following command to show the interface names. Run the following command to show the interface names. Run the following command to show the interface names.

# ifconfig OR # ip addr 

The interface ' enp0s3 ' is the LAN device connected to my computer and the IP Address is ' 10.0.2.15 '. The other interface ' lo ' ( Loopback ) which is nothing but the local network of the computer within itself. Thus my computer is only connected to one interface, ' enp0s3 '. The interface ' enp0s3 ' is the LAN device connected to my computer and the IP Address is ' 10.0.2.15 '. The other interface ' lo ' ( Loopback ) which is nothing but the local network of the computer within itself. Thus my computer is only connected to one interface, ' enp0s3 '. Configuring Static IP Address in CentOS Go to directory ' /etc/sysconfig/network-scripts ' and list the files; you should see a file corresponding to your network interface. Go to directory ' /etc/sysconfig/network-scripts ' and list the files; you should see a file corresponding to your network interface.

$ cd /etc/sysconfig/network-scripts $ ls 

Open the file 'ifcfg-enp0s3' using ' Open the file 'ifcfg-enp0s3' using ' Vim ' or any editor of your choice. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set. Set the following values for the variables. Change the values according to the IP address and subnet that you need to set.

Save and exit the file. Restart the networking service with the following commands: Save and exit the file. Restart the networking service with the following commands:

# nmcli networking off # nmcli networking on 

Finally, run ' ifconfig ' again to verify if static IP has been set. Finally, run ' ifconfig ' again to verify if static IP has been set.

# ifconfig 

Conclusion

Mar 12, 2021 | www.linuxshelltips.com

In this article, we saw an easy way to set an IP address in CentOS. The example, in this case, is a static IP on the local network, i.e., it is not a static public IP over the Internet.

To set a static public IP address over the Internet, you need to purchase the IP Address and configure it in the file as shown above, along with other details like DNS server, network prefix, which will be provided by your Internet Service Provider.

Thanks a lot for reading and let us know your thoughts in the comments below!

[Apr 06, 2019] IP Aliasing Assigning multiple IP addresses to single NIC - LinuxTechLab

Apr 06, 2019 | linuxtechlab.com

IP Aliasing : Assigning multiple IP addresses to single NIC

by Shusain · Published April 3, 2019 · Updated April 4, 2019

In this tutorial, we are going to learn to assign multiple IP addresses to a single NIC (Network Interface Card). This process of assigning multiple addresses to a single network interface is called IP aliasing.

Main advantage of using IP aliasing is that we don't need multiple NICs to configure multiple IPs, hence saving us cost & configuration time. IP aliasing is most useful when using Apache IP based virtual hosting.

For this tutorial, we are going to use RHEL/CentOS 7 but the same process can also be used older versions of RHEL/CentOS, the only change being the name of the network interfaces other than that process is same.

Recommended Read: Top 7 commands for Linux Network Traffic Monitoring

Also Read: Monitoring network bandwidth with iftop command

Network interfaces files in RHEL/CentOS 7(on older versions as well) are located at ' /etc/sysconfig/network-scripts ' & name of the interfaces are usually ' ifcfg-en0sX ', where ' X ' is the number of the interface. In my case, its ' ifcfg-en0s0' . So we will be using the same for the purpose of this tutorial.

Using Network Manager

We will be using a tool called 'nmtui' for this method. NMTUI is command line based user interface for Network Manager & even works for the system that does not have GUI installed. Open terminal & enter the command,

$ nmtui

We will get the following window,

<img src="https://i0.wp.com/linuxtechlab.com/wp-content/uploads/2019/04/IP-Alias-1.png?resize=425%2C366&#038;ssl=1" alt="IP aliasing" width="425" height="366" data-recalc-dims="1" />

Click on 'Edit a connection', & then select the network interface from the list of interfaces & press ENTER key,

<img src="https://i1.wp.com/linuxtechlab.com/wp-content/uploads/2019/04/IP-Alias-2.png?resize=795%2C618&#038;ssl=1" alt="IP aliasing" width="795" height="618" srcset="https://i1.wp.com/linuxtechlab.com/wp-content/uploads/2019/04/IP-Alias-2.png?w=795&amp;ssl=1 795w, https://i1.wp.com/linuxtechlab.com/wp-content/uploads/2019/04/IP-Alias-2.png?resize=768%2C597&amp;ssl=1 768w" sizes="(max-width: 795px) 100vw, 795px" data-recalc-dims="1" />
Now we add the required number of IP address here & once done, we can click on 'OK' & then exit from the nmtui menu. Restart the NetworkManager service & we will have our IP aliasing ready.

Manual Method

For this method, we will manually create the necessary files needed. We will assign two different IPs in addition to the one we have already assigned to our interface ' ifcfg-en0s0' . To create IP alias, we are going to use our default network interface file & then will create two copies of the file with names 'ifcfg-en0s0:1 ' & 'ifcfg-en0s0:2'

$ cd /etc/sysconfig/network-scripts
$ cp ifcfg- en0s0 ifcfg- en0s0 :1
$ cp ifcfg- en0s0 ifcfg- en0s0 :2

Now, let's open primary network interface i.e. eth0, & see its content

$ vi ifcfg- en0s0

DEVICE=" en0s0 "
BOOTPROTO=static
ONBOOT=yes
TYPE="Ethernet"
IPADDR=192.168.1.100
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
HWADDR=32:0A:21:54:ND:6D

We will now configure our other network interfaces, we only need to make changes for 'DEVICE' & 'IPADDR' for aliasing

$ vi ifcfg- en0s0 :1

DEVICE=" en0s0 :1″
BOOTPROTO=static
ONBOOT=yes
TYPE="Ethernet"
IPADDR=192.168.1.110
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
HWADDR=32:0A:21:54:ND:6D

& same is to be done for 'ifcfg:eth0:2'

$ vi ifcfg- en0s0 :2

DEVICE=" en0s0 :2″
BOOTPROTO=static
ONBOOT=yes
TYPE="Ethernet"
IPADDR=192.168.1.120
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
HWADDR=32:0A:21:54:ND:6D

Save both files & restart the network service for changes to take effect.

$ systemctl restart network

To check IP addresses have bee assigned or not, run 'ifconfig'

$ ifconfig

<img src="https://i0.wp.com/linuxtechlab.com/wp-content/uploads/2017/03/ifconfig.jpg?resize=545%2C301&#038;ssl=1" alt="ip aliasing" width="545" height="301" srcset="https://i0.wp.com/linuxtechlab.com/wp-content/uploads/2017/03/ifconfig.jpg?w=545&amp;ssl=1 545w, https://i0.wp.com/linuxtechlab.com/wp-content/uploads/2017/03/ifconfig.jpg?resize=300%2C166&amp;ssl=1 300w" sizes="(max-width: 545px) 100vw, 545px" data-recalc-dims="1" />

This completes our tutorial, if you are having any issues/comments, please do mention them in the comment box below.

[Feb 04, 2019] How to disable NetworkManager on CentOS - RHEL 7 by admin

Feb 04, 2019 | www.thegeekdiary.com

Disabling NetworkManager

The following steps will disable NetworkManager service and allows the interface to be managed only by network service.

1. To check which are the interfaces managed by NetworkManager

# nmcli device status

This displays a table that lists all network interfaces along with their STATE. If Network Manager is not controlling an interface, its STATE will be listed as unmanaged . Any other value indicates the interface is under Network Manager control.

2. Stop the NetworkManager service:

# systemctl stop NetworkManager

3. Disable the service permanently:

# systemctl disable NetworkManager

4. To confirm the NetworkManager service has been disabled

# systemctl list-unit-files | grep NetworkManager

5. Add the below parameter in /etc/sysconfig/network-scripts/ifcfg-ethX of interfaces that are managed by NetworkManager to make it unmanaged.

NM_CONTROLLED="no"

Note: Be sure to change the NM_CONTROLLED="yes" to " no " or the network service may complain about "Connection activation failed" when it cannot find an interface to start Switching to "network" service

When the NetworkManager is disabled, the interface can be configured for use with the network service. Follow the steps below to configure and interface using network services.

1. Set the IP address in the configuration file: /etc/sysconfig/network-scripts/ifcfg-eth0. Set the NM_CONTROLLED value to no and assign a static IP address in the file.

NAME="eth0"
HWADDR=...
ONBOOT=yes
BOOTPROTO=none
IPADDR=...
NETMASK=...
GATEWAY=...
TYPE=Ethernet
NM_CONTROLLED=no

2. Set the DNS servers to be used by adding into the file: /etc/resolv.conf :

nameserver [server 1]
nameserver [server 2]

3. Enable the network service

# systemctl enable network

4. Restart the network service

# systemctl restart network

CentOS / RHEL 5, 6 : how to disable NetworkManager
Linux OS Service 'NetworkManager'

[Jan 30, 2019] How to take back control of /etc/resolv.conf on Linux

Jan 30, 2019 | www.ctrl.blog

Opting-out of NetworkManager

NetworkManager is by far the most common auto-configuration tool for the entire networking stack including DNS resolution. It's responsible for /etc/resolv.conf on many popular distribution including Debian and Fedora. After you've disable other programs that manages resolv.conf, you may also discover that NetworkManager will jump in to fill the job -- as happens on Ubuntu 16.10 and later.

Set the dns option in the main configuration section to none to disable DNS handling in NetworkManager. The below commands sets this option in a new conf.d/no-dns.conf configuration file, restarts the NetworkManager service, and deletes the NetworkManager-generated resolv.conf file.

   echo -e "[main]\ndns=none" > /etc/NetworkManager/conf.d/no-dns.conf
   systemctl restart NetworkManager.service
   rm /etc/resolv.conf

If you discover that NetworkManager is still managing your resolv.conf, then you may have a configuration conflict (usually caused by dnsmasq). Recursively search through your NetworkManager configuration to discover any conflicts.

   grep -ir /etc/NetworkManager/

Refer to the last section of this article for instructions on recreating a /etc/resolv.conf file with manual configuration

Disabling Network Manager

OpenStack networking currently does not work on systems that have the Network Manager (NetworkManager) service enabled. The Network Manager service is currently enabled by default on Red Hat Enterprise Linux installations where one of these package groups was selected during installation:

• Desktop
• Software Development Workstation

The Network Manager service is not currently enabled by default on Red Hat Enterprise Linux installations where one of these package groups was selected during installation:

• Basic Server
• Database Server
• Web Server
• Identity Management Server
• Virtualization Host
• Minimal Install

Follow the steps listed in this procedure while logged in as the root user on each system in the environment that will handle network traffic. This includes the system that will host the OpenStack Networking service, all network nodes, and all compute nodes.

These steps ensure that the NetworkManager service is disabled and replaced by the standard network service for all interfaces that will be used by OpenStack Networking.

1. Verify Network Manager is currently enabled using the chkconfig command.

   # chkconfig --list NetworkManager

   The output displayed by the chkconfig command inicates whether or not the Network Manager service is enabled.
   • The system displays an error if the Network Manager service is not currently installed:

     error reading information on service NetworkManager: No such file or directory

     If this error is displayed then no further action is required to disable the Network Manager service.
   • The system displays a list of numerical run levels along with a value of on or off indicating whether the Network Manager service is enabled when the system is operating in the given run level.

     NetworkManager 	0:off	1:off	2:off	3:off	4:off	5:off	6:off

     If the value displayed for all run levels is off then the Network Manager service is disabled and no further action is required. If the value displayed for any of the run levels is on then the Network Manager service is enabled and further action is required.
2. Ensure that the Network Manager service is stopped using the service command.

   # service NetworkManager stop

3. Ensure that the Network Manager service is disabled using the chkconfig command.

   # chkconfig NetworkManager off

4. Open each interface configuration file on the system in a text editor. Interface configuration files are found in the /etc/sysconfig/network-scripts/ directory and have names of the form ifcfg-X where X is replaced by the name of the interface. Valid interface names include eth0, p1p5, and em1.

   In each file ensure that the NM_CONTROLLED configuration key is set to no and the ON_BOOT configuration key is set to yes.

   NM_CONTROLLED=no
   ONBOOT=yes

   This action ensures that the standard network service will take control of the interfaces and automatically activate them on boot.
5. Ensure that the network service is started using the service command.

   # service network start

6. Ensure that the network service is enabled using the chkconfig command.

   # chkconfig network on

The Network Manager service has been disabled. The standard network service has been enabled and configured to control the required network interfaces.

[Aug 05, 2017] Disabling NetworkManager on RHEL 7

Aug 01, 2017 | superuser.com

Andrew 46

I was setting up a RHEL7 server in vmware vSphere and I'm having trouble getting it on the network without NetworkManager. I configured the server to have a static IP during the install process and it set everything up using NetworkManager. While this does work we do not use NetworkManager in my office, so I went and entered what we usually put the config file to get RHEL6 servers online without NetworkManager.

/etc/sysconfig/network-scripts/ifcfg-ens192 is the following:

NAME=ens192
TYPE=Ethernet
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=10.0.2.15
PREFIX=24
GATEWAY=10.0.2.2

However when I disable NetworkManager the network service fails to start with the following error

#service network restart

Restarting network (via systemctl): Job for network.service failed. See 'systemctl status network.service' and 'journalctl -xn' for details.

And both commands output the following:

network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
network[1838]: RTNETLINK answers: File exists
systemd[1]: network.service: control process exited, code=exited status=1
systemd[1]: Failed to start LSB: Bring up/down networking

Also, here's what the command 'ip addr' outputs:

1: lo: mtu 65536 qdisc noqueue state UNKNOWN
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: ens192: mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 08:00:27:98:8e:df brd ff:ff:ff:ff:ff:ff
asked Jul 11 '14 at 22:19

Pavel Šimerda Apr 5 '15 at 5:40

I recently debugged an issue with network.service and the best way to track the ip commands was strace . You shouldn't generally get this type of error. It might be worth reporting (ideally via support). –

nickg Oct 25 '14 at 16:46

Check your MAC Address for the VM. It should be 08:00:27:98:8e:df since that is what is shown you ran ip addr. If it's anything else, you will need to set it in your ifcfg-ens192 file with the following, but replace the address with the actual.

HWADDR="08:00:27:98:8e:df"

I had the same issue and this solved it for me.

Pavel Šimerda Apr 5 '15 at 5:43

The configuration file in the Question apparently relies on NAME=ens192 without any MAC address matching.

Dec 30 '14 at 14:46 0ldd0g

All I found that it takes to resolve this is that MAC in the Config

 NAME=ens192
 TYPE=Ethernet
 ONBOOT=yes
 HWADDR="08:00:27:98:8e:df"
 NM_CONTROLLED=no
 BOOTPROTO=static
 IPADDR=10.0.2.15
 PREFIX=24
 GATEWAY=10.0.2.2

If you are not sure of the hardware address you can find it in.

 cat /sys/class/net/ens192/address

you should put that information (GATEWAY=10.0.2.2) in /etc/sysconfig/network once it's done, restarting the service should succeed

Try to go to the virtual machine network settings and make sure the network cable is connected and check if you have blocked this with a firewall

NetworkManager dictates the default route ( ip route ) even though your interface has nm disabled, it is just that interface not the whole system.

ps aux | grep -I net   # will probably find NetworkManager still running.
chkconfig NetworkManager off
systemctl disable NetworkManager.service

systemctl disable doesn't stop a service, nor does chkconfig ... off which basically translates to the same command anyway. – Pavel Šimerda

I too came across "Failed to start LSB: Bring up/down networking" error, since disabling NetworkManager. It took two minutes to be brought up interfaces after boot. The cause of confusion was "... LSB". It turned out the message comes out from just the traditional /etc/rc.d/init.d/network script. In my case, following solved the problem;

To network-scripts/ifcfg-eth0 added

NMCONTROLLED=no

Removed unnecessary ifcfg-* files which NetworkManager has left behind

# rm /etc/sysconfig/network-scripts/ifcfg-Wired_connection_?

Abdullah  May 11 at 10:26

This will solve the problem!

# rm /etc/udev/rules.d/70-persistent-ipoib.rules 

# reboot

• Now edit /etc/sysconfig/network-scripts/ifcfg-eth0,
• Add new HWADDR generated or remove it
• Remove UUID line

-Restart the networking service

 #systemctl restart network.service

NOW! Working.

I was having the same issue. So I just delete the backup files I made in /etc/sysconfig/network-scripts , such as ifcfg-Bridge_connection_1.home and ifcfg-Bridge_connection_1.office which I created for backup usage. They should not be created there. The /etc/init.d/network restart could work well after delete those useless ifcfg-*.

[Aug 02, 2017] Issue with RHEL7 and disabling NetworkManager

Aug 02, 2017 | serverfault.com

cjmaio Jul 2 '14 at 15:14

Okay community, let's see if we can figure this one out, cause I'm out of answers.

Where I work I am setting up a bunch of RedHat Enterprise Linux servers. There is a collection of RHEL6 and RHEL7 servers.

---

On the RHEL6 servers, I am using the standard network configuration tool by configuring it in /etc/sysconfig/network-scripts/ifcfg-eth0 and a dhclient configuration file in /etc/dhclient-eth0.conf . Everything works properly, I am assigned the custom FQDN by our DNS servers (e.g. hostname.ad.company.tld ) and when the DHCP lease is up, it is renewed automatically.

---

Here is the issue:

In RHEL7, NetworkManager is enabled by default. On our Kickstart, I have removed NetworkManager and went back to configuring network and dhcp the way it is done in RHEL6. All of the configuration is the same (sans using /etc/sysconfig/network-scripts/ifcfg-ens192 instead of eth0) and works fine for the first DHCP lease.

Once the lease is up, it seemingly doesn't renew it until I issue a systemctl restart network command.

---

I have looked and looked and I am coming up short. There must be something different in RHEL7 or something not configured when you disable NetworkManager , but I cannot for the life of me figure it out.

Anyone have any thoughts?

As I know these usually help, I'll post my RHEL7 configuration files, and the snippet from the logs where it loses the DHCP lease.

---

/etc/sysconfig/network-scripts/ifcfg-ens192

# Generated by dracut initrd
DEVICE="ens192"
ONBOOT=yes
NETBOOT=yes
UUID="c23045ff-7b60-4dff-b052-30a61923a852"
IPV6INIT=yes
BOOTPROTO=dhcp
HWADDR="00:0c:29:b6:d8:cc"
TYPE=Ethernet
NAME="ens192"
NM_CONTROLLED=no

/etc/dhclient-ens192.conf

send host-name "hostname";
send fqdn.fqdn "hostname.ad.company.tld";
send fqdn.server-update off;

/var/log/messages

Jun 27 23:06:09 sa-kbwiki01 avahi-daemon[591]: Withdrawing address record for 129.89.78.221 on ens192.
Jun 27 23:06:09 sa-kbwiki01 avahi-daemon[591]: Leaving mDNS multicast group on interface ens192.IPv4 with address xxx.xx.xx.xxx.
Jun 27 23:06:09 sa-kbwiki01 avahi-daemon[591]: Interface ens192.IPv4 no longer relevant for mDNS.

That log snippet doesn't show your DHCP lease being lost. Keep looking, there should be other more relevant entries. – Michael Hampton ♦ Jul 2 '14 at 15:24

From what I recall hearing pre-launch is that networkManager is not the same PoS it was years ago and Red Hat more or less forces you to learn to live with it. Having said that, the documentation mentions that NetworkManager has been made responsible for starting dhclient, so it could be that without NM, dhclient is run with the -1 option and doesn't become a daemon. – HBruijn ♦ Jul 2 '14 at 15:36

@MichaelHampton I do not see anything else in /var/log/messages. Other things that use the network are operating fine until that line, at which point everything starts saying no network available. – cjmaio Jul 2 '14 at 15:59

@HBruijn That gives me somewhere to start... though when doing a ps aux | grep dhclient I do see that the -1 flag is being set... is there anywhere else that dhclient would log to other than /var/log/messages ? – cjmaio Jul 2 '14 at 16:00

Yeah, NM is fairly safe to use these days unless you have a very complicated setup. I do wonder why you're running Avahi though. – Michael Hampton ♦ Jul 2 '14 at 16:01

Recommended Links

Introducing NetworkManager by Rosanna Yuen January 2005

How to disable Network Manager on Linux - Linux FAQ

nmcli(1) tool for controlling NetworkManager - Linux man page

networkmanager.conf(5) - Linux man page

[ifupdown]

This section contains ifupdown-specific options and thus only has effect when using ifupdown plugin.

managed=false | true

Controls whether interfaces listed in the 'interfaces' file are managed by NetworkManager. If set to true, then interfaces listed in /etc/network/interfaces are managed by NetworkManager. If set to false, then any interface listed in /etc/network/interfaces will be ignored by NetworkManager. Remember that NetworkManager controls the default route, so because the interface is ignored, NetworkManager may assign the default route to some other interface. When the option is missing, false value is taken as default.

nm-system-settings.conf(5) - Linux man page

nm-tool(1) - Linux man page

Ubuntu Manpage nmcli - command-line tool for controlling NetworkManager

Etc

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotes :  Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce :  Bernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS :  Programming Languages History : PL/1 : Simula 67 : C : History of GCC development :  Scripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month :  How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D

The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the Softpanorama society. We do not warrant the correctness of the information provided or its fitness for any purpose. The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Last modified: April, 06, 2019