Estou usando o Centos 7 em execução no Oracle VM VirtualBox Manager. Eu queria que meu windows (host) fosse capaz de pingar Centos 7 (convidado) então eu mudei as configurações de rede em VM para usar adaptador de rede somente host que funcionou bem como minhas janelas podem pingar ip da máquina vm mas máquina VM não tem conexão de rede . Parece ser um problema com o gateway padrão, como definir o gateway padrão? Qual é o valor correto do gateway padrão? para que haja conexão de rede disponível para a máquina vm.
Captura de tela da rede que não tem rota e DNS padrão
[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
Esse é o comportamento esperado. A utilização da rede somente para host permite apenas conexões entre o host e a VM, ou entre VMs no mesmo host , como o nome sugere. No manual: "... e as máquinas virtuais não podem falar com o mundo fora do host, uma vez que elas não estão conectadas a uma interface de rede física".
Se você quiser estabelecer conexões de rede do host para o convidado e do convidado para o mundo externo, provavelmente desejará um adaptador de rede em ponte.
Tags networking virtualbox ping gateway linux