CentOS 新增網卡

[狀況]：VirtualBox 安裝 CentOS 7 已有一張網卡正常運作。之後再從 VirtualBox 新增一張網卡，CentOS 7 沒辦法自動設定完成。

[手動解決]：
找出目前所有網卡

# dmesg | grep -in eth
387:[    2.074571] e1000 0000:00:03.0 eth0: (PCI:33MHz:32-bit) 08:00:27:37:d5:5a
388:[    2.074587] e1000 0000:00:03.0 eth0: Intel(R) PRO/1000 Network Connection
412:[    2.571363] e1000 0000:00:08.0 eth1: (PCI:33MHz:32-bit) 08:00:27:03:28:44
413:[    2.571371] e1000 0000:00:08.0 eth1: Intel(R) PRO/1000 Network Connection
417:[    2.588359] systemd-udevd[244]: renamed network interface eth1 to enp0s8
420:[    2.597290] systemd-udevd[241]: renamed network interface eth0 to enp0s3

找出新網卡名稱
對照 ifconfig 的訊息，可判斷出新網卡的名稱為 enp0s8

# ifconfig
enp0s3: flags=4163  mtu 1500
        inet 192.168.56.101  netmask 255.255.255.0  broadcast 192.168.56.255
        inet6 fe80::a00:27ff:fe37:d55a  prefixlen 64  scopeid 0x20
        ether 08:00:27:37:d5:5a  txqueuelen 1000  (Ethernet)
        RX packets 6911  bytes 3960745 (3.7 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 6048  bytes 1263062 (1.2 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

其他(目前系統上的網卡名稱)：

# cat /proc/net/dev
Inter-|   Receive                                                |  Transmit
 face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed
enp0s3:    3448      25    0    0    0     0          0         0     5770      64    0    0    0     0       0          0
enp0s8:   26607     173    0    0    0     0          0         0    27360     154    0    0    0     0       0          0
    lo:     656       8    0    0    0     0          0         0      656       8    0    0    0     0       0          0

產生新網卡的 UUID

# uuidgen enp0s8
297daa1e-a83d-471e-b70d-83eafb2f2470

找出新網卡 mac address
可由第1步驟輸出訊息可找出為 08:00:27:03:28:44

建立新網卡設定檔
複製舊的修改

# cd /etc/sysconfig/network-scripts/
# cp ifcfg-enp0s3 ifcfg-enp0s8

NAME、UUID、DEVICE、HWADDR修改為新網卡資料

# vi ifcfg-enp0s8
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=enp0s8
UUID=297daa1e-a83d-471e-b70d-83eafb2f2470
DEVICE=enp0s8
HWADDR=08:00:27:03:28:44
ONBOOT=yes
PEERDNS=yes
PEERROUTES=yes
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes

啟動新網卡

# ifup enp0s8

# ifconfig
enp0s3: flags=4163  mtu 1500
        inet 192.168.56.101  netmask 255.255.255.0  broadcast 192.168.56.255
        inet6 fe80::a00:27ff:fe37:d55a  prefixlen 64  scopeid 0x20
        ether 08:00:27:37:d5:5a  txqueuelen 1000  (Ethernet)
        RX packets 9110  bytes 5349053 (5.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 7662  bytes 1562108 (1.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp0s8: flags=4163  mtu 1500
        inet 192.168.0.124  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::a00:27ff:fe03:2844  prefixlen 64  scopeid 0x20
        ether 08:00:27:03:28:44  txqueuelen 1000  (Ethernet)
        RX packets 441  bytes 43254 (42.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 63  bytes 10391 (10.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

其他：指定固定IP設定

TYPE="Ethernet" #可略
BOOTPROTO="static" #可略
DEFROUTE="yes" #可略
IPV4_FAILURE_FATAL="no" #可略
IPV6INIT="yes" #可略
IPV6_AUTOCONF="yes" #可略
IPV6_DEFROUTE="yes" #可略
IPV6_FAILURE_FATAL="no" #可略
NAME="enp0s8"
UUID="297daa1e-a83d-471e-b70d-83eafb2f2470"
DEVICE="enp0s8"
ONBOOT="yes"
IPADDR="192.168.56.102"
PREFIX="24"
#GATEWAY="192.168.56.1" #VirtualBox Host-only Adapter(另用NAT訪問internet)
DNS1="8.8.8.8" #可略
IPV6_PEERDNS="yes" #可略
IPV6_PEERROUTES="yes" #可略
IPV6_PRIVACY="no" #可略

參考：
生活點點滴滴: VirtualBox CentOS 新增網卡
CentOS virtualbox no icfg-eth1 when adding secondary network interface
How to change configuration of eth0 without restarting other interface (CentOS, Redhat)