无法连接到工作互联网的Centos7服务器 – 不能ping，SSH等

当前设置

我正在从通过可启动的USB安装的最小的iso文件安装全新的centos 7。

电脑是一个老式的苹果机器，运行centos 7之前没有问题。

该机器有1个帐户，名为“mas”。

问题

我无法从机器外部访问端口80或22。

情况

机器似乎不接受任何传入的连接。 Ping没有回应，ssh没有回答。
当sshing进入服务器，[/var/log/messages,/var/log/audit/audit.log]都保持不变，无论帐户。
Firewalld确实有启动警告，但它们都与ipv6有关。
通过本地主机连接到本地服务器的所有连接都没有问题
Selinux执行不是问题 – 行为是相同的，当执行是宽容的。

例如：

curl "localhost" -- Receive default Centos page. ssh mas@localhost -- Continues to ask for password, works after.

上述行为与127.0.0.1相同。

##编辑##

 ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 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: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 10:9a:dd:49:14:28 brd ff:ff:ff:ff:ff:ff inet 192.168.0.106/24 brd 192.168.0.255 scope global enp3s0 valid_lft forever preferred_lft forever inet6 fe80::1408:ba9e:471c:e2c8/64 scope link valid_lft forever preferred_lft forever ip r default via 192.168.0.1 dev enp3s0 proto static metric 100 192.168.0.0/24 dev enp3s0 proto kernel scope link src 192.168.0.106 metric 100 iptables-save [blank] telnet -nlp Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1056/sshd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1334/master tcp6 0 0 :::22 :::* LISTEN 1056/sshd tcp6 0 0 ::1:25 :::* LISTEN 1334/master udp 0 0 0.0.0.0:11000 0.0.0.0:* 865/dhclient udp 0 0 0.0.0.0:68 0.0.0.0:* 865/dhclient udp 0 0 127.0.0.1:323 0.0.0.0:* 729/chronyd udp6 0 0 :::55079 :::* 865/dhclient udp6 0 0 ::1:323 :::* 729/chronyd raw6 0 0 :::58 :::* 7 744/NetworkManager Active UNIX domain sockets (only servers) Proto RefCnt Flags Type State I-Node PID/Program name Path unix 2 [ ACC ] STREAM LISTENING 19789 1334/master private/tlsmgr unix 2 [ ACC ] STREAM LISTENING 19792 1334/master private/rewrite unix 2 [ ACC ] STREAM LISTENING 19795 1334/master private/bounce unix 2 [ ACC ] STREAM LISTENING 19798 1334/master private/defer unix 2 [ ACC ] STREAM LISTENING 19801 1334/master private/trace unix 2 [ ACC ] STREAM LISTENING 19807 1334/master public/flush unix 2 [ ACC ] STREAM LISTENING 19804 1334/master private/verify unix 2 [ ACC ] STREAM LISTENING 19230 1334/master private/proxymap unix 2 [ ACC ] STREAM LISTENING 19233 1334/master private/proxywrite unix 2 [ ACC ] STREAM LISTENING 19236 1334/master private/smtp unix 2 [ ACC ] STREAM LISTENING 19239 1334/master private/relay unix 2 [ ACC ] STREAM LISTENING 19245 1334/master private/error unix 2 [ ACC ] STREAM LISTENING 19248 1334/master private/retry unix 2 [ ACC ] STREAM LISTENING 19251 1334/master private/discard unix 2 [ ACC ] STREAM LISTENING 11827 1/systemd /run/lvm/lvmetad.socket unix 2 [ ACC ] STREAM LISTENING 19254 1334/master private/local unix 2 [ ACC ] STREAM LISTENING 19257 1334/master private/virtual unix 2 [ ACC ] STREAM LISTENING 19260 1334/master private/lmtp unix 2 [ ACC ] STREAM LISTENING 19263 1334/master private/anvil unix 2 [ ACC ] STREAM LISTENING 19266 1334/master private/scache unix 2 [ ACC ] STREAM LISTENING 12608 1/systemd /run/lvm/lvmpolld.socket unix 2 [ ACC ] STREAM LISTENING 19242 1334/master public/showq unix 2 [ ACC ] STREAM LISTENING 18006 744/NetworkManager /var/run/NetworkManager/private-dhcp unix 2 [ ACC ] STREAM LISTENING 12415 1/systemd /run/systemd/private unix 2 [ ACC ] STREAM LISTENING 19778 1334/master public/pickup unix 2 [ ACC ] STREAM LISTENING 19782 1334/master public/cleanup unix 2 [ ACC ] STREAM LISTENING 19785 1334/master public/qmgr unix 2 [ ACC ] SEQPACKET LISTENING 12461 1/systemd /run/udev/control unix 2 [ ACC ] STREAM LISTENING 7111 1/systemd /run/systemd/journal/stdout unix 2 [ ACC ] STREAM LISTENING 14320 1/systemd /var/run/dbus/system_bus_socket unix 2 [ ACC ] STREAM LISTENING 14323 1/systemd /var/run/pcscd/pcscd.comm

EDIT2

 firewall-cmd --state running firewall-cmd --list-all drop (active) target: DROP icmp-block-inversion: no interfaces: enp3s0 sources: services: ports: protocols: masquerade: no forward-ports: source-ports: icmp-blocks: rich rules:

CentOS 7上的默认防火墙不是iptables而是firewalld 。

iptables被禁用，但firewalld处于活动状态。

你可以完全禁用firewalld ：

 systemctl stop firewalld systemctl disable firewalld

或者您可以为您的服务添加允许规则：

 firewall-cmd --zone=public --add-port=80/tcp --permanent firewall-cmd --zone=public --add-port=22/tcp --permanent firewall-cmd --reload

– 编辑设置firewalld

 firewall-cmd --get-active-zones firewall-cmd --get-zone-of-interface=enp3s0

您可以定义区域编辑/etc/sysconfig/network-scripts/ifcfg-enp3s0

 ZONE=public

将区域关联到您的networking接口：

 firewall-cmd --zone=public --add-interface=enp3s0