我正在使用在 Oracle VM VirtualBox Manager 中运行的 Centos 7。我希望我的 Windows（主机）能够 ping Centos 7（来宾），因此我更改了虚拟机中的网络设置以使用仅主机网络适配器，该适配器运行良好，因为我的 Windows 可以 ping 虚拟机 IP，但虚拟机没有网络连接。好像是默认网关的问题，请问如何设置默认网关？默认网关的正确值是多少？这样虚拟机就有可用的网络连接。
[root@hostname sysconfig]# ifconfig -a
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 0.0.0.0
inet6 fe80::42:48ff:fe73:32ae prefixlen 64 scopeid 0x20<link>
ether 02:42:48:73:32:ae txqueuelen 0 (Ethernet)
RX packets 1086312 bytes 190220822 (181.4 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 2244812 bytes 1153561488 (1.0 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.101 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::a00:27ff:fe57:e658 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:57:e6:58 txqueuelen 1000 (Ethernet)
RX packets 1083 bytes 112900 (110.2 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 166 bytes 24915 (24.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 70229 bytes 8733878 (8.3 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 70229 bytes 8733878 (8.3 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth0022793: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::541a:3bff:fefe:40fc prefixlen 64 scopeid 0x20<link>
ether 56:1a:3b:fe:40:fc txqueuelen 0 (Ethernet)
RX packets 206 bytes 15300 (14.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5850 bytes 272760 (266.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth0333914: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 16:78:ed:04:52:5e txqueuelen 0 (Ethernet)
RX packets 68480 bytes 84562622 (80.6 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 90298 bytes 14502209 (13.8 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth06f16da: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::4aa:47ff:fe36:c394 prefixlen 64 scopeid 0x20<link>
ether 06:aa:47:36:c3:94 txqueuelen 0 (Ethernet)
RX packets 51 bytes 4678 (4.5 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5823 bytes 267358 (261.0 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth16e581d: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::2cb7:66ff:fe1a:a627 prefixlen 64 scopeid 0x20<link>
ether 2e:b7:66:1a:a6:27 txqueuelen 0 (Ethernet)
RX packets 8 bytes 648 (648.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5769 bytes 262582 (256.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth1ecf198: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::2022:c4ff:fe1c:9ab5 prefixlen 64 scopeid 0x20<link>
ether 22:22:c4:1c:9a:b5 txqueuelen 0 (Ethernet)
RX packets 8 bytes 648 (648.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5773 bytes 262882 (256.7 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth8536f91: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::ac21:2fff:fe0e:87e6 prefixlen 64 scopeid 0x20<link>
ether ae:21:2f:0e:87:e6 txqueuelen 0 (Ethernet)
RX packets 841994 bytes 71927871 (68.5 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1841996 bytes 992110236 (946.1 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethda88d72: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::f44c:52ff:fe6c:b856 prefixlen 64 scopeid 0x20<link>
ether f6:4c:52:6c:b8:56 txqueuelen 0 (Ethernet)
RX packets 8 bytes 648 (648.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5759 bytes 261746 (255.6 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:ce:19:b8 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0-nic: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 52:54:00:ce:19:b8 txqueuelen 500 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@hostname network-scripts]# cat /etc/sysconfig/network-scripts/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=dc80dadc-3072-428f-888f-25dc8dcd8ca9
DEVICE=enp0s3
ONBOOT=no
[root@hostname network-scripts]# cat /etc/sysconfig/network-scripts/ifcfg-lo
DEVICE=lo
IPADDR=127.0.0.1
NETMASK=255.0.0.0
NETWORK=127.0.0.0
[root@hostname network-scripts]# cat /etc/resolv.conf
# Generated by NetworkManager
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
[root@hostname sysconfig]# ip route show
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
192.168.56.0/24 dev enp0s3 proto kernel scope link src 192.168.56.101 metric 100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
[root@hostname sysconfig]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
192.168.56.0 0.0.0.0 255.255.255.0 U 100 0 0 enp0s3
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
[root@hostname sysconfig]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
192.168.56.0 0.0.0.0 255.255.255.0 U 100 0 0 enp0s3
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
[root@hostname sysconfig]# ifconfig enp0s3
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.101 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::a00:27ff:fe57:e658 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:57:e6:58 txqueuelen 1000 (Ethernet)
RX packets 1070 bytes 110928 (108.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 164 bytes 24513 (23.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@hostname sysconfig]# netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
192.168.56.0 0.0.0.0 255.255.255.0 U 0 0 0 enp0s3
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
[root@hostname sysconfig]# ip route list
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
192.168.56.0/24 dev enp0s3 proto kernel scope link src 192.168.56.101 metric 100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
[root@hostname sysconfig]# ping google.com
ping: unknown host google.com
[root@hostname sysconfig]# nslookup google.com
;; connection timed out; trying next origin
;; connection timed out; no servers could be reached
答案1
这是预期的行为。使用仅主机顾名思义，网络仅允许主机和虚拟机之间或同一主机上的虚拟机之间的连接。手册中写道：“……虚拟机无法与主机外部的世界通信，因为它们没有连接到物理网络接口。”
如果您希望能够建立从主机到访客的网络连接和从访客到外部世界，您可能需要一个桥接网络适配器。