Network Configuration for centos 6 and 7

Network Configuration for centos 6 and 7

As centos7 has changed with the previous release, and the network attribute has changed a lot, the network configuration before centos7 and 7 is explained here separately.

1. Related configuration files
In RHEL, CentOS, and other Redhat Linux systems, the main network-related configuration files are as follows:

/Etc/host. conf configure the control file of the Domain Name Service Client
/Etc/hosts ing host names to IP addresses
The configuration file of the/etc/resolv. conf Domain Name Service client, used to specify the location of the Domain Name Server
/Etc/sysconfig/network contains the most basic network information of the host for system startup.
/Etc/sysconfig/network-script/Some network Information initialized at system startup
/Etc/xinetd. conf defines the network service started by the super process xinetd.
/Etc/networks maps domain names to network addresses
/Etc/protocols sets the protocol used by the host and the protocol numbers of each Protocol
/Etc/services: Set network services with different ports on the host

Ii. Detailed description of the configuration file

1. IP, MASK, GW, and DNS configuration files:/etc/sysconfig/network-scripts/ifcfg-IFACE

DEVICE =: the name of the associated DEVICE, which must be consistent with the "INTERFACE_NAME" in the second half of the file name; BOOTPROTO = {satic | none | dhcp | bootp}: Boot Protocol. To use a static address, use static or none. dhcp indicates that the dhcp server is used to obtain the address; IPADDR =: IP address; NETMASK =: subnet mask; GATEWAY =: Set the default GATEWAY; ONBOOT =: whether to automatically activate this network interface at startup; HWADDR =: hardware address, which must be consistent with the address in the hardware; save; USERCTL={ yes | No}: whether normal users are allowed to control this interface; PEERDNS={ yes | No}: whether to accept the dns address specified by the dhcp server when BOOTPROTO is dhcp;

How to configure the configuration file:

USERCTL: whether normal users can control this device; PEERDNS: If the BOOTPROTO value is "dhcp", whether to allow the dns server allocated by dhcpserver to directly overwrite the information /etc/resolv . Conf file;

Note: After the configuration file is configured, restart the service to take effect.

2. route-related configuration file:/etc/sysconfig/network-scripts/route-IFACE

Two styles:

(1)TARGETviaGW (2) define a route for each three rows ADDRESS #=TARGET NETMASK #=mask GATEWAY #=GW

3. Configure multiple addresses for the NIC:

ifconfig : ifconfig IFACE_ALIAS ip ipaddradd

Configuration file:

ifcfg-IFACE_ALIAS DEVICE=IFACE_ALIAS

Note: The Gateway alias cannot be guided using the dhcp protocol;

4. Linux Network attribute graphical Configuration tool tui (textuserinterface ):

System-config-network-tui. You can also use setup to find the network configuration;

Note: Remember to restart the network service to make it take effect;

5. Configure the Host Name of the current host:

1>. hostname [HOSTNAME] /etc/sysconfig/network 2>.HOSTNAME=

6. The network interface identifies and names the related udev configuration file:

/etc/udev/rules .d /70-persistent-net .rules

7. Uninstall the NIC Driver:

modprobe-re1000

Iii. CentOS7 network attribute Configuration

1. Traditional name: Ethernet eth [0, 1, 2,...], wlan [0, 1, 2,...]

2. udev supports multiple naming schemes:

Firmware, topology

3. Nic naming mechanism

Systemd naming for network devices:

(A) if the index information provided by the Firmware or BIOS integration device on the master board is available and predictable, name the index, for example, eno1; (B) if the index information provided by Firmware or BIOS for the PCI-E expansion slot is available and predictable, name the index, such as ens1; (C) if the physical location information of the hardware interface is available, name it, for example, enp2s0; (D) If you start the service explicitly, you can also name it based on the MAC address, enx2387a1dc56; (E) If none of the above are available, the traditional naming mechanism is used; Some of the above naming mechanisms require the participation of the biosdevname program;

4. Name format

en:ethernet wl:wlan ww:wwan Name type: O <index>: The device index Number of the Integrated Device; S <slot>: Index Number of the expansion slot; X <MAC>: MAC address-based naming; p<bus>s<slot>:enp2s1

5. Nic device naming process:

Step 1: udev, auxiliary tool Program /lib/udev/rename_device , /usr/lib/udev/rules .d /60-net .rules Step 2: biosdevname /usr/lib/udev/rules .d /71-biosdevname .rules Step 3: Check the network interface device according /usr/lib/udev/rules .d /75-net-description ID_NET_NAME_ONBOARD,ID_NET_NAME_SLOT,ID_NET_NAME_PATH

6. Return to the traditional naming method:

(1) Edit /etc/default/grub Configuration File GRUB_CMDLINE_LINUX= "net.ifnames=0rhgbquiet" (2) generate its configuration file for grub2 grub2-mkconfig-o /etc/grub2 .cfg (3) restart the system init6

7. Address Configuration tool: nmcli

nmcli[OPTIONS]OBJECT{COMMAND|help} device-showandmanagenetworkinterfaces connection-start,stop,andmanagenetworkconnections

8. How to modify attributes such as IP addresses:

#nmcliconnectionmodifyIFACE[+|-]setting.propertyvalue setting.property: ipv4.addresses ipv4.gateway ipv4.dns1 ipv4.method manual

9. Network Interface Configuration tui tool: nmtui

10. Host Name Configuration tool: hostnamectl

status set - hostname

4. Different network configurations of Centos7 and earlier releases

1. Different startup Methods

Previous versions: /etc/init .d /network/ start|status|stop|restart Servicenetworkstart|status|stop|restart Centos7：systemctlstart|status|stop|restartnetwork.service

2. Different network interface naming methods

Earlier versions: eth0, 1, 2 ...... Centos7：enoxxxxxxxx

3. Some configuration files are different.

4. Similarities: The methods for modifying the configuration file when setting static addresses are the same.