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连接：网络不可达？- ping

tag-icon • tag-icon networking server network-manager dns
连接：网络不可达？- ping

当我尝试 ping google 的 dns 或任何外部网络时，我得到了什么 connect: Network is unreachable？

我无法更新，我认为这是

我是网络新手……也是 Ubuntu 新手。但这些是我认为可能有帮助的一些命令的结果

$ ip a
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
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:0e:7f:a9:10:54 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.5/24 brd 192.168.0.255 scope global eth0
    inet6 fe80::20e:7fff:fea9:1054/64 scope link 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN 
    link/ether 86:0b:cb:43:63:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
mcserver@helloworld:~$ 

$ vi /etc/resolv.conf:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 192.168.0.5
nameserver 8.8.8.8

$ vi /etc/network/interfaces
# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 192.168.0.5
        netmask 255.255.255.0
        network 192.168.1.0
        broadcast 192.168.0.255
        post-up iptables-restore < /etc/iptables.up.rules
        dns-nameservers 192.168.0.5 8.8.8.

答案1

以下行是错误的：

iface eth0 inet static
    address 192.168.0.5
    netmask 255.255.255.0
    network 192.168.1.0 <<<<<<<<<<<<<<<<<<<<<<<< It should be 192.168.0.0
    broadcast 192.168.0.255
    post-up iptables-restore < /etc/iptables.up.rules
    dns-nameservers 192.168.0.5 8.8.8.8

此外，似乎没有任何默认网关设置。

由于没有关于您的网络的更多信息，我建议在末尾添加以下行：

    gateway <YOUR.ROUTER.IP.ADDRESS>

因此，假设您的路由器 IP 地址是 192.168.0.1，这将是整个条目：

iface eth0 inet static
    address 192.168.0.5
    netmask 255.255.255.0
    network 192.168.0.0
    broadcast 192.168.0.255
    post-up iptables-restore < /etc/iptables.up.rules
    gateway 192.168.0.1
    dns-nameservers 192.168.0.5 8.8.8.8

答案2

问题是你需要设置默认网关

  1. 搭乘航站楼

  2. 输入

    sudo ip route add default via <your gateway>(eg:192.168.136.1) dev eth0

  3. 有时您将能够 ping ( ping 8.8.8.8) 但浏览器中没有互联网连接，然后：

  4. 去sudo nano /etc/resolv.conf

  5. 添加nameserver 8.8.8.8

  6. 添加nameserver <your gateway>或nameserver 127.0.1.1

  7. sudo /etc/init.d/networking restart或者sudo service networking restart

答案3

您可能需要添加默认网关。以 root 用户身份执行此命令。

例如

root@localhost:~# route add default gw 172.23.5.1

您可以从 eth0/eoM 获取前 3 个八位字节，即 172.23.5

然后 ping 一个 IP 来查看连接是否有效。

root@localhost:~# ping 10.56.94.81    
PING 10.56.94.81 (10.56.94.81) 56(84) bytes of data.    
64 bytes from 10.56.94.81: icmp_seq=1 ttl=62 time=0.203 ms    
64 bytes from 10.56.94.81: icmp_seq=2 ttl=62 time=0.197 ms    
64 bytes from 10.56.94.81: icmp_seq=3 ttl=62 time=0.210 ms    
^C    
--- 10.56.94.81 ping statistics ---    
3 packets transmitted, 3 received, 0% packet loss, time 2033ms    
rtt min/avg/max/mdev = 0.197/0.203/0.210/0.012 ms

答案4

就我的情况而言，如果您的系统位于防火墙后面，则无法与互联网交互。除非您为 HTTP/HTTPS/FTP 指定代理服务器，否则无法访问。

尝试这个：

export  http_proxy=http://yourcompanyproxy.company.com:1234   
export  ftp_proxy=ftp://yourcompanyproxy.company.com:1234  
export  https_proxy=https://yourcompanyproxy.company.com:1234

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