Ubuntu网络配置

Posted by wsxq2 on 2018-12-10
TAGS:  网络   Ubuntu   Linux  

Solving “RTNETLINK answers: File exists” when running ifup

查看路由（网关）设置？

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ip route
ip route help

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route

查看 DNS 设置？

  1. resolv.conf: Linux 中 DNS 配置的主要文件。只要它配置了正确的 namesever IP 即可正确使用 DNS。相关的 manual 为man resolv.conf 
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       $ cat /etc/resolv.conf
   # 显示可能如下
   # 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 202.117.112.3
  2. nslookup: Linux 中用于检查 DNS 是否正确配置的命令，基本使用如下： 
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    $ nslookup www.baidu.com
Server:         202.117.112.3
Address:        202.117.112.3#53
   
Non-authoritative answer:
www.baidu.com   canonical name = www.a.shifen.com.
Name:   www.a.shifen.com
Address: 180.149.131.98
Name:   www.a.shifen.com
Address: 180.149.132.151

设置 DNS？

  1. 在/etc/network/interface中设置如下： 
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    auto enp0s9
iface enp0s9 inet static
    address 192.168.2.16/24
    gateway 192.168.2.1
    dns-nameservers 202.117.112.3 # 重点是此行

    参见man 8 resolvconf。此外，Linux 还有可能会通过网关自动设置 DNS

  2. 修改/etc/resolvconf/resolv.conf.d/base（这个文件默认是空的）在里面插入： 
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    nameserver 202.117.112.3
nameserver 8.8.8.8

    修改好保存，然后执行

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    $ resolvconf -u
$ cat /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 202.117.112.3
nameserver 8.8.8.8
$ ping baidu.com
PING baidu.com (220.181.57.216) 56(84) bytes of data.
64 bytes from 220.181.57.216: icmp_seq=1 ttl=52 time=25.7 ms
64 bytes from 220.181.57.216: icmp_seq=2 ttl=52 time=25.8 ms
64 bytes from 220.181.57.216: icmp_seq=3 ttl=52 time=26.1 ms
^C
--- baidu.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 25.741/25.918/26.153/0.253 ms

    参考自：Ubuntu下修改DNS重启也能用的方法

查看 物理（MAC）地址？

  1. ip: Linux 中用于取代传统的 ifconfig命令，是iproute2软件包的一部分。iproute2软件包中另一个常用的命令是ss，用于取代传统的netstat。更多相关信息，请参考试试Linux下的ip命令，ifconfig已经过时了 
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    $ dpkg -S `which ip` # 查看 ip 命令属于哪个软件包
iproute2: /sbin/ip
$ dpkg -L iproute2|grep bin/ # 查看 iproute2 软件包中所有的命令
/usr/bin/routef
/usr/bin/routel
/usr/bin/lnstat
/usr/bin/nstat
/usr/sbin/arpd
/usr/sbin/genl
/bin/ss
/bin/ip
/sbin/rtacct
/sbin/tc
/sbin/rtmon
/sbin/bridge
/sbin/tipc
/usr/bin/rtstat
/usr/bin/ctstat
/sbin/ip
$ ip help
Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }
       ip [ -force ] -batch filename
where  OBJECT := { link | address | addrlabel | route | rule | neighbor | ntable |
                   tunnel | tuntap | maddress | mroute | mrule | monitor | xfrm |
                   netns | l2tp | fou | tcp_metrics | token | netconf }
       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |
                    -h[uman-readable] | -iec |
                    -f[amily] { inet | inet6 | ipx | dnet | mpls | bridge | link } |
                    -4 | -6 | -I | -D | -B | -0 |
                    -l[oops] { maximum-addr-flush-attempts } | -br[ief] |
                    -o[neline] | -t[imestamp] | -ts[hort] | -b[atch] [filename] |
                    -rc[vbuf] [size] | -n[etns] name | -a[ll] | -c[olor]}
$ ip ad help
Usage: ip address {add|change|replace} IFADDR dev IFNAME [ LIFETIME ]
                                                      [ CONFFLAG-LIST ]
       ip address del IFADDR dev IFNAME [mngtmpaddr]
       ip address {show|save|flush} [ dev IFNAME ] [ scope SCOPE-ID ]
                            [ to PREFIX ] [ FLAG-LIST ] [ label LABEL ] [up]
       ip address {showdump|restore}
IFADDR := PREFIX | ADDR peer PREFIX
          [ broadcast ADDR ] [ anycast ADDR ]
          [ label IFNAME ] [ scope SCOPE-ID ]
SCOPE-ID := [ host | link | global | NUMBER ]
FLAG-LIST := [ FLAG-LIST ] FLAG
FLAG  := [ permanent | dynamic | secondary | primary |
           [-]tentative | [-]deprecated | [-]dadfailed | temporary |
           CONFFLAG-LIST ]
CONFFLAG-LIST := [ CONFFLAG-LIST ] CONFFLAG
CONFFLAG  := [ home | nodad | mngtmpaddr | noprefixroute | autojoin ]
LIFETIME := [ valid_lft LFT ] [ preferred_lft LFT ]
LFT := forever | SECONDS

    简单用法：

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    $ ip ad # 查看各接口的启用与否、IP地址、MAC地址信息
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 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: enp0s3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 08:00:27:b2:80:2e brd ff:ff:ff:ff:ff:ff
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 08:00:27:c6:4e:bf brd ff:ff:ff:ff:ff:ff
    inet 192.168.56.16/24 brd 192.168.56.255 scope global enp0s8
       valid_lft forever preferred_lft forever
    inet6 fe80::a00:27ff:fec6:4ebf/64 scope link
       valid_lft forever preferred_lft forever
4: enp0s9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 08:00:27:4b:67:b7 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.16/24 brd 192.168.2.255 scope global enp0s9
       valid_lft forever preferred_lft forever
    inet6 fe80::a00:27ff:fe4b:67b7/64 scope link
       valid_lft forever preferred_lft forever
$ sudo ip link set enp0s3 up # 启用接口 enp0s3

    关于该命令的具体用法，请参考man ip

    关于ss命令，可通过ss -h查看用法，常用的用法为sudo ss -laut4p。

查看 IP 地址？

  1. ip: 参见前述

开机启动时依然禁用某个网络接口？

  1. https://serverfault.com/questions/585852/disable-a-network-interface-on-booting-ubuntu

    You can add the interfaces that should not come up on boot on a new file /etc/network/interfaces.noboot, then bring them up when needed with:

    sudo ifup -i /etc/network/interfaces.noboot -v eth1

  2. 在/etc/network/interfaces文件中注释掉auto <interface_name>及相应的内容，如下所示：

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    # The primary network interface
# auto enp0s3
# iface enp0s3 inet dhcp

2 用作路由器，作网关？

Ubuntu下双网卡简单静态内网路由器

链接