CentOS 7 NW settings

Introduction

A memo about the network settings of CentOS7

Network settings

Manage network settings with the NetworkManager service

• Device representing NIC
• Connection (settings applied to the device)

Associate connection (settings) with the device

Checking predefined devices ** CONNECTION connects **

# nmcli d
DEVICE   TYPE      STATE     CONNECTION 
enp0s25 ethernet connected enp0s25
lo loopback No management-- 

Checking predefined connections

# nmcli c
NAME     UUID                                  TYPE      DEVICE  
enp0s25  173098fd-54de-48b1-95a1-ceaa687089ab  ethernet  enp0s25 

Definition of new connection

• ** Associate a new connection with the newly connected NIC **
• With nmcli -d there is a device but no connection

Create a connection with nmcli and nmtui and connect the device nmtui can be set with GUI

Creating a VLAN device

Create VLAN77

# nmcli c add type vlan ifname vlan77 con-name vlan-vlan77 dev enp0s25 id 77
Connect'vlan-vlan77' (1092e677-f16b-4a35-8839-19739d20a011)Was added successfully.

  1 VLAN=yes
  2 TYPE=Vlan
  3 PHYSDEV=enp0s25
  4 VLAN_ID=77
  5 REORDER_HDR=yes
  6 GVRP=no
  7 MVRP=no
  8 PROXY_METHOD=none
  9 BROWSER_ONLY=no
 10 BOOTPROTO=dhcp
 11 DEFROUTE=yes
 12 IPV4_FAILURE_FATAL=no
 13 IPV6INIT=yes
 14 IPV6_AUTOCONF=yes
 15 IPV6_DEFROUTE=yes
 16 IPV6_FAILURE_FATAL=no
 17 IPV6_ADDR_GEN_MODE=stable-privacy
 18 NAME=vlan-vlan77
 19 UUID=1092e677-f16b-4a35-8839-19739d20a011
 20 DEVICE=vlan77
 21 ONBOOT=yes

Set the IP address on

Confirmation of vlan device operation

 cat /proc/net/vlan/config 
VLAN Dev name    | VLAN ID
Name-Type: VLAN_NAME_TYPE_RAW_PLUS

Details

# cat /proc/net/vlan/vlan77 
vlan77  VID: 77  REORDER_HDR: 1  dev->priv_flags: 1
         total frames received            0
          total bytes received            0
      Broadcast/Multicast Rcvd            0

      total frames transmitted           13
       total bytes transmitted         1022
Device: enp0s25
INGRESS priority mappings: 0:0  1:0  2:0  3:0  4:0  5:0  6:0 7:0
 EGRESS priority mappings: