Hi CentOS users,

I have install CentOS 7 in VirtualBox, and want the guest CentOS using dynamic IP address (The network type is bridged). I find the guest CentOS can works OK when using ethernet cable, but can't get IP address via wireless network. I also posted this issue on stackoverflow (http://superuser.com/questions/922045/how-does-the-guest-os-of-virtualbox-ge...).

(1) The "ip addr" command outputs: 1: lo: <LOOPBACK,UP,LOWER_UP> 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: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:bc:e1:67 brd ff:ff:ff:ff:ff:ff

(2) The content of ifcfg-enp0s3: TYPE="Ethernet" BOOTPROTO="dhcp" DEFROUTE="yes" PEERDNS="yes" PEERROUTES="yes" IPV4_FAILURE_FATAL="no" IPV6INIT="yes" IPV6_AUTOCONF="yes" IPV6_DEFROUTE="yes" IPV6_PEERDNS="yes" IPV6_PEERROUTES="yes" IPV6_FAILURE_FATAL="no" NAME="enp0s3" UUID="6d221230-f35b-44da-9536-a4e9acfa2bc2" DEVICE="enp0s3" ONBOOT="yes"

(3) The network related logs from /var/log/messages:

Jun 4 01:52:40 CentOS kernel: drop_monitor: Initializing network drop monitor service Jun 4 01:52:40 CentOS kernel: e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI Jun 4 01:52:41 CentOS kernel: e1000 0000:00:03.0 eth0: Intel(R) PRO/1000 Network Connection Jun 4 01:52:41 CentOS systemd-udevd[234]: renamed network interface eth0 to enp0s3 Jun 4 01:52:47 CentOS systemd: Starting Import network configuration from initramfs... Jun 4 01:52:47 CentOS systemd: Started Import network configuration from initramfs. Jun 4 01:52:51 CentOS systemd: Starting Network Manager... Jun 4 01:52:51 CentOS NetworkManager[689]: <info> NetworkManager (version 1.0.0-14.git20150121.b4ea599c.el7) is starting... Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Read config: /etc/NetworkManager/NetworkManager.conf and conf.d: 10-ibft-plugin.conf Jun 4 01:52:51 CentOS NetworkManager[689]: <info> WEXT support is disabled Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Acquired D-Bus service com.redhat.ifcfgrh1 Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Loaded plugin ifcfg-rh: (c) 2007 - 2013 Red Hat, Inc. To report bugs please use the NetworkManager mailing list. Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Loaded plugin iBFT: (c) 2014 Red Hat, Inc. To report bugs please use the NetworkManager mailing list. Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Loaded plugin keyfile: (c) 2007 - 2013 Red Hat, Inc. To report bugs please use the NetworkManager mailing list. Jun 4 01:52:51 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-lo ... Jun 4 01:52:51 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-enp0s3 ... Jun 4 01:52:51 CentOS NetworkManager[689]: <info> read connection 'enp0s3' Jun 4 01:52:51 CentOS NetworkManager[689]: <info> monitoring kernel firmware directory '/lib/firmware'. Jun 4 01:52:51 CentOS systemd: Started Network Manager. Jun 4 01:52:51 CentOS systemd: Starting LSB: Bring up/down networking... Jun 4 01:52:51 CentOS NetworkManager[689]: <info> WiFi enabled by radio killswitch; enabled by state file Jun 4 01:52:51 CentOS NetworkManager[689]: <info> WWAN enabled by radio killswitch; enabled by state file Jun 4 01:52:51 CentOS NetworkManager[689]: <info> WiMAX enabled by radio killswitch; enabled by state file Jun 4 01:52:51 CentOS NetworkManager[689]: <info> Networking is enabled by state file Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (lo): link connected Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (lo): carrier is ON Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (lo): new Generic device (driver: 'unknown' ifindex: 1) Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (lo): exported as /org/freedesktop/NetworkManager/Devices/0 Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (enp0s3): carrier is OFF Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (enp0s3): new Ethernet device (driver: 'e1000' ifindex: 2) Jun 4 01:52:51 CentOS NetworkManager[689]: <info> (enp0s3): exported as /org/freedesktop/NetworkManager/Devices/1 Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2] Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): preparing device Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): link connected Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): device state change: unavailable -> disconnected (reason 'carrier-changed') [20 30 40] Jun 4 01:52:52 CentOS NetworkManager[689]: <info> Auto-activating connection 'enp0s3'. Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: starting connection 'enp0s3' Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) scheduled... Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) started... Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): device state change: disconnected -> prepare (reason 'none') [30 40 0] Jun 4 01:52:52 CentOS NetworkManager[689]: <info> NetworkManager state is now CONNECTING Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) scheduled... Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) complete. Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) starting... Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): device state change: prepare -> config (reason 'none') [40 50 0] Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) successful. Jun 4 01:52:52 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) complete. Jun 4 01:52:52 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-lo ... Jun 4 01:52:52 CentOS network: Bringing up loopback interface: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo' Jun 4 01:52:52 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-lo ... Jun 4 01:52:52 CentOS network: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo' Jun 4 01:52:52 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-lo ... Jun 4 01:52:52 CentOS network: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo' Jun 4 01:52:53 CentOS NetworkManager[689]: <info> parsing /etc/sysconfig/network-scripts/ifcfg-lo ... Jun 4 01:52:53 CentOS network: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo' Jun 4 01:52:53 CentOS network: [ OK ] Jun 4 01:52:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) scheduled. Jun 4 01:52:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) started... Jun 4 01:52:53 CentOS NetworkManager[689]: <info> (enp0s3): device state change: config -> ip-config (reason 'none') [50 70 0] Jun 4 01:52:53 CentOS NetworkManager[689]: <info> Activation (enp0s3) Beginning DHCPv4 transaction (timeout in 45 seconds) Jun 4 01:52:53 CentOS NetworkManager[689]: <info> dhclient started with pid 1140 Jun 4 01:52:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) complete. Jun 4 01:52:53 CentOS network: Bringing up interface enp0s3: [ OK ] Jun 4 01:52:53 CentOS systemd: Started LSB: Bring up/down networking. Jun 4 01:52:53 CentOS systemd: Starting Network. Jun 4 01:52:53 CentOS systemd: Reached target Network. Jun 4 01:52:53 CentOS dhclient[1140]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x623c8c73) Jun 4 01:52:59 CentOS dhclient[1140]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x623c8c73) Jun 4 01:53:06 CentOS dhclient[1140]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 7 (xid=0x28b9690d) Jun 4 01:53:13 CentOS dhclient[1140]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 17 (xid=0x28b9690d) Jun 4 01:53:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) scheduled... Jun 4 01:53:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) started... Jun 4 01:53:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) complete. Jun 4 01:53:30 CentOS dhclient[1140]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 14 (xid=0x28b9690d) Jun 4 01:53:38 CentOS NetworkManager[689]: <warn> (enp0s3): DHCPv4 request timed out. Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed unknown -> timeout Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): canceled DHCP transaction, DHCP client pid 1140 Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed timeout -> done Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) scheduled... Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) started... Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5] Jun 4 01:53:38 CentOS NetworkManager[689]: <info> NetworkManager state is now DISCONNECTED Jun 4 01:53:38 CentOS NetworkManager[689]: <info> startup complete Jun 4 01:53:38 CentOS NetworkManager[689]: <warn> (enp0s3): Activation: failed for connection 'enp0s3' Jun 4 01:53:38 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) complete. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): device state change: failed -> disconnected (reason 'none') [120 30 0] Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): deactivating device (reason 'none') [0] Jun 4 01:53:39 CentOS NetworkManager[689]: <info> Auto-activating connection 'enp0s3'. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: starting connection 'enp0s3' Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) scheduled... Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) started... Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): device state change: disconnected -> prepare (reason 'none') [30 40 0] Jun 4 01:53:39 CentOS NetworkManager[689]: <info> NetworkManager state is now CONNECTING Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) scheduled... Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) complete. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) starting... Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): device state change: prepare -> config (reason 'none') [40 50 0] Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) successful. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) complete. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) scheduled. Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) started... Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): device state change: config -> ip-config (reason 'none') [50 70 0] Jun 4 01:53:39 CentOS NetworkManager[689]: <info> Activation (enp0s3) Beginning DHCPv4 transaction (timeout in 45 seconds) Jun 4 01:53:39 CentOS NetworkManager[689]: <info> dhclient started with pid 2365 Jun 4 01:53:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) complete. Jun 4 01:53:39 CentOS dhclient[2365]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x224ada0f) Jun 4 01:53:42 CentOS dhclient[2365]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x224ada0f) Jun 4 01:53:46 CentOS dhclient[2365]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x224ada0f) Jun 4 01:53:54 CentOS dhclient[2365]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 7 (xid=0x1de75b49) Jun 4 01:54:01 CentOS dhclient[2365]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 11 (xid=0x1de75b49) Jun 4 01:54:10 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) scheduled... Jun 4 01:54:10 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) started... Jun 4 01:54:10 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) complete. Jun 4 01:54:12 CentOS dhclient[2365]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 21 (xid=0x1de75b49) Jun 4 01:54:23 CentOS NetworkManager[689]: <warn> (enp0s3): DHCPv4 request timed out. Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed unknown -> timeout Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): canceled DHCP transaction, DHCP client pid 2365 Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed timeout -> done Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) scheduled... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) started... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5] Jun 4 01:54:23 CentOS NetworkManager[689]: <info> NetworkManager state is now DISCONNECTED Jun 4 01:54:23 CentOS NetworkManager[689]: <warn> (enp0s3): Activation: failed for connection 'enp0s3' Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) complete. Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): device state change: failed -> disconnected (reason 'none') [120 30 0] Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): deactivating device (reason 'none') [0] Jun 4 01:54:23 CentOS NetworkManager[689]: <info> Auto-activating connection 'enp0s3'. Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: starting connection 'enp0s3' Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) scheduled... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) started... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): device state change: disconnected -> prepare (reason 'none') [30 40 0] Jun 4 01:54:23 CentOS NetworkManager[689]: <info> NetworkManager state is now CONNECTING Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) scheduled... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) complete. Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) starting... Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): device state change: prepare -> config (reason 'none') [40 50 0] Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) successful. Jun 4 01:54:23 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) complete. Jun 4 01:54:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) scheduled. Jun 4 01:54:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) started... Jun 4 01:54:24 CentOS NetworkManager[689]: <info> (enp0s3): device state change: config -> ip-config (reason 'none') [50 70 0] Jun 4 01:54:24 CentOS NetworkManager[689]: <info> Activation (enp0s3) Beginning DHCPv4 transaction (timeout in 45 seconds) Jun 4 01:54:24 CentOS NetworkManager[689]: <info> dhclient started with pid 2393 Jun 4 01:54:24 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) complete. Jun 4 01:54:24 CentOS dhclient[2393]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x77843ed1) Jun 4 01:54:29 CentOS dhclient[2393]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0x77843ed1) Jun 4 01:54:41 CentOS dhclient[2393]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 4 (xid=0xe3a3af6) Jun 4 01:54:45 CentOS dhclient[2393]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 5 (xid=0xe3a3af6) Jun 4 01:54:50 CentOS dhclient[2393]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 12 (xid=0xe3a3af6) Jun 4 01:54:55 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) scheduled... Jun 4 01:54:55 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) started... Jun 4 01:54:55 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) complete. Jun 4 01:55:02 CentOS dhclient[2393]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 14 (xid=0xe3a3af6) Jun 4 01:55:08 CentOS NetworkManager[689]: <warn> (enp0s3): DHCPv4 request timed out. Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed unknown -> timeout Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): canceled DHCP transaction, DHCP client pid 2393 Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed timeout -> done Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) scheduled... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) started... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5] Jun 4 01:55:08 CentOS NetworkManager[689]: <info> NetworkManager state is now DISCONNECTED Jun 4 01:55:08 CentOS NetworkManager[689]: <warn> (enp0s3): Activation: failed for connection 'enp0s3' Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) complete. Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): device state change: failed -> disconnected (reason 'none') [120 30 0] Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): deactivating device (reason 'none') [0] Jun 4 01:55:08 CentOS NetworkManager[689]: <info> Auto-activating connection 'enp0s3'. Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: starting connection 'enp0s3' Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) scheduled... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) started... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): device state change: disconnected -> prepare (reason 'none') [30 40 0] Jun 4 01:55:08 CentOS NetworkManager[689]: <info> NetworkManager state is now CONNECTING Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) scheduled... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 1 of 5 (Device Prepare) complete. Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) starting... Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): device state change: prepare -> config (reason 'none') [40 50 0] Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) successful. Jun 4 01:55:08 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 2 of 5 (Device Configure) complete. Jun 4 01:55:09 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) scheduled. Jun 4 01:55:09 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) started... Jun 4 01:55:09 CentOS NetworkManager[689]: <info> (enp0s3): device state change: config -> ip-config (reason 'none') [50 70 0] Jun 4 01:55:09 CentOS NetworkManager[689]: <info> Activation (enp0s3) Beginning DHCPv4 transaction (timeout in 45 seconds) Jun 4 01:55:09 CentOS NetworkManager[689]: <info> dhclient started with pid 2421 Jun 4 01:55:09 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 3 of 5 (IP Configure Start) complete. Jun 4 01:55:09 CentOS dhclient[2421]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0xc0de211) Jun 4 01:55:12 CentOS dhclient[2421]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0xc0de211) Jun 4 01:55:16 CentOS dhclient[2421]: DHCPREQUEST on enp0s3 to 255.255.255.255 port 67 (xid=0xc0de211) Jun 4 01:55:27 CentOS dhclient[2421]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 4 (xid=0x281d5ba3) Jun 4 01:55:31 CentOS dhclient[2421]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 10 (xid=0x281d5ba3) Jun 4 01:55:34 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 4 (xid=0x3e3fe85b) Jun 4 01:55:38 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 5 (xid=0x3e3fe85b) Jun 4 01:55:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) scheduled... Jun 4 01:55:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) started... Jun 4 01:55:39 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv6 Configure Timeout) complete. Jun 4 01:55:41 CentOS dhclient[2421]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 7 (xid=0x281d5ba3) Jun 4 01:55:43 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 12 (xid=0x3e3fe85b) Jun 4 01:55:48 CentOS dhclient[2421]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 11 (xid=0x281d5ba3) Jun 4 01:55:53 CentOS NetworkManager[689]: <warn> (enp0s3): DHCPv4 request timed out. Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed unknown -> timeout Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): canceled DHCP transaction, DHCP client pid 2421 Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): DHCPv4 state changed timeout -> done Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) scheduled... Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) started... Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5] Jun 4 01:55:53 CentOS NetworkManager[689]: <info> NetworkManager state is now DISCONNECTED Jun 4 01:55:53 CentOS NetworkManager[689]: <info> Disabling autoconnect for connection 'enp0s3'. Jun 4 01:55:53 CentOS NetworkManager[689]: <warn> (enp0s3): Activation: failed for connection 'enp0s3' Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): Activation: Stage 4 of 5 (IPv4 Configure Timeout) complete. Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): device state change: failed -> disconnected (reason 'none') [120 30 0] Jun 4 01:55:53 CentOS NetworkManager[689]: <info> (enp0s3): deactivating device (reason 'none') [0] Jun 4 01:55:55 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 11 (xid=0x3e3fe85b) Jun 4 01:56:06 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 17 (xid=0x3e3fe85b) Jun 4 01:56:23 CentOS dhclient[2425]: DHCPDISCOVER on enp0s3 to 255.255.255.255 port 67 interval 12 (xid=0x3e3fe85b) Jun 4 01:56:35 CentOS dhclient[2425]: No DHCPOFFERS received. Jun 4 01:56:35 CentOS dhclient[2425]: No working leases in persistent database - sleeping.

Could anyone give some comments? Thanks very much! Best Regards Nan Xiao