一：Linux的网络属性配置：
(1)网络分层的作用
物理层：用于界定网络设备接口标准，电器特性等硬件标准
数据链路层：识别网络设备，数据校验，帧的开始和结束
网络层：IP通讯最佳路径选择
传输层：三次握手，流量控制，丢包重传，传输协议TCP/UDP
会话层：客户端与服务端建立会话
表示层：数据传输的加密、压缩、编码等
应用层：计算机通讯之间的应用
(2)Linux主机接入网络的方式
IP/NETMASK:实现本地网络通信
路由(网关)：可以进行跨网络通信
DNS服务器：基于主机名的通信，linux可以最多有三个DNS地址
(3)DNS服务器配置文件：/etc/resolv.conf
配置格式：
nameserver 114.114.114.114
二：使用命令配置汇总
(1)ifcfg家族
ifocnfig: 配置IP，NETMASK
route:路由
netstat：状态机统计数据查看
(2)iproute家族
ip OBJECT
addr：地址和掩码
link：接口
route：路由
ss：状态及统计数据查看
(3)CentOS 7：nm 家族
nmcli：命令行工具
nmtui：text window工具
三、ifcfg家族配置管理
(1)ifconfig命令:配置网络接口
ifconfig [-a] [interface]
-a:查看当前系统上所有网络接口的状态及详细信息，包括非活动状态的接口
CentOS 7 显示参数详解：
eno16777736：网卡名称
inet：ip地址
netmask：子网掩码
broadcast：广播地址
UP：网卡表示激活状态
BPOADCAST:支持广播功能
MNLTICAST:支持组播功能
RUNNING：处于运行状态
mtu：网卡最大传输单元
inet6：表示IPV6地址
ether：以太网地址，表示mac地址
txqueuelen：传输队列长度
RX packets 5 bytes 440(440.0B)：接收到报文的数量、接收到报文的大小
RX errors：接收到错误报文的数量
dropped：丢包的数量
overruns：溢出的数量
TX packets 5 bytes 440 (440.0 B)：传出报文的数量、传出报文的大小
TX errors 0：传出报文的错误数量
dropped：发送出去丢包的数量
CentOS 6 ifconfig显示参数详解
eth0：网卡名称
Link encap：接口类型
inet addr：IP地址
Bcast：广播地址
Mask：子网掩码
inet6 addr：IPV6地址
UP：网卡表示激活状态
BROADCAST：支持广播功能
MULTICAST:支持组播功能
RUNNING：处于运行状态
mtu：网卡的最大传输单元
ether：以太网地址，表示mac地址
txqueuelen：传输队列长度
其他的同上
可以指定接口名称，单独查看
[root@localhost ~]# ifconfig eno16777736 eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.0.0.8 netmask 255.0.0.0 broadcast 10.255.255.255 inet6 fe80::20c:29ff:fe8e:1df3 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:8e:1d:f3 txqueuelen 1000 (Ethernet) RX packets 57826 bytes 80877374 (77.1 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 14050 bytes 1058269 (1.0 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
修改网络配置：
方法一：
# ifconfig eno16777736 10.0.0.8/8 up # ifconfig eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.0.0.8 netmask 255.0.0.0 broadcast 10.255.255.255 inet6 fe80::20c:29ff:fe8e:1df3 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:8e:1d:f3 txqueuelen 1000 (Ethernet) RX packets 58044 bytes 80895700 (77.1 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 14176 bytes 1077665 (1.0 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions
注意：此配置仅临时有效，重启网络服务或者重启系统，内核会重读配置文件
方法二：
# ifconfig eno16777736 10.0.0.8 netmask 255.0.0.0 up # ifconfig eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 10.0.0.8 netmask 255.0.0.0 broadcast 10.255.255.255 inet6 fe80::20c:29ff:fe8e:1df3 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:8e:1d:f3 txqueuelen 1000 (Ethernet) RX packets 58194 bytes 80908451 (77.1 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 14248 bytes 1087805 (1.0 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
四: route 命令：查看即管理理由
命令格式：
route add [-net|-host] target [netmask NM] [gw GW] [dev]
-net:表示添加网络路由
-host：表示添加主机路由
gw：为默认网关
查看:
route -n
# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.0.0.254 0.0.0.0 UG 100 0 0 eno16777736 0.0.0.0 172.18.0.1 0.0.0.0 UG 101 0 0 eno33554984 10.0.0.0 0.0.0.0 255.0.0.0 U 100 0 0 eno16777736 172.18.0.0 0.0.0.0 255.255.0.0 U 100 0 0 eno33554984
添加路由：
# route add -net 192.168.0.0/24 gw 10.0.0.254 dev eno16777736 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.0.0.254 0.0.0.0 UG 100 0 0 eno16777736 0.0.0.0 172.18.0.1 0.0.0.0 UG 101 0 0 eno33554984 10.0.0.0 0.0.0.0 255.0.0.0 U 100 0 0 eno16777736 172.18.0.0 0.0.0.0 255.255.0.0 U 100 0 0 eno33554984 192.168.0.0 10.0.0.254 255.255.255.0 UG 0 0 0 eno16777736 [root@localhost ~]#
删除路由：
# route del -net 192.168.0.0/24 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.0.0.254 0.0.0.0 UG 100 0 0 eno16777736 0.0.0.0 172.18.0.1 0.0.0.0 UG 101 0 0 eno33554984 10.0.0.0 0.0.0.0 255.0.0.0 U 100 0 0 eno16777736 172.18.0.0 0.0.0.0 255.255.0.0 U 100 0 0 eno33554984
五: netstat命令:打印网络连接，路由表，接口等信息
netstat：
-t：tcp协议相关链接，和连接状态
-u：udp协议相关连接
-w：raw socket相关的链接
-l：处于监听状态的链接
-a：显示所有状态
-n：以数字格式显示IP和port
-e：扩展格式
-p：显示相关的进程及PID
常用组合：
# netstat -tan Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN tcp 0 52 10.0.0.8:22 10.0.0.1:54649 ESTABLISHED tcp6 0 0 :::22 :::* LISTEN tcp6 0 0 ::1:25 :::* LISTEN # netstat -uan Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State udp 0 0 0.0.0.0:12315 0.0.0.0:* udp 0 0 0.0.0.0:68 0.0.0.0:* udp6 0 0 :::26322 :::* # netstat -tunlp 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 1373/sshd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 2491/master tcp6 0 0 :::22 :::* LISTEN 1373/sshd tcp6 0 0 ::1:25 :::* LISTEN 2491/master udp 0 0 0.0.0.0:12315 0.0.0.0:* 3510/dhclient udp 0 0 0.0.0.0:68 0.0.0.0:* 3510/dhclient udp6 0 0 :::26322 :::* 3510/dhclient
显示路由表: netstat -rn
-r:显示内核路由表
-n：数字格式显示
# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 10.0.0.254 0.0.0.0 UG 0 0 0 eno16777736 0.0.0.0 172.18.0.1 0.0.0.0 UG 0 0 0 eno33554984 10.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 eno16777736 172.18.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eno33554984
显示接口的统计数据：
netstat -i
# netstat -i Kernel Interface table Iface MTU RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eno16777 1500 58877 0 0 0 14620 0 0 0 BMRU eno33554 1500 2530 0 0 0 173 0 0 0 BMRU lo 65536 5 0 0 0 5 0 0 0 LRU
注释： Iface：接口
MTU:最大传输单元
RX-OK：成功接收报文的数量
RX-ERR：失败接收报文的数量
RX-OVR：接收溢出报文的数量
TX-OK：成功传输报文的数量
TX-ERR：失败传输报文的数量
TX-DRP：传出丢弃的报文数量
TX-OVR：传出溢出的报文数量
Flg：标志
六：ifup/ifdown命令
CentOS 6：在使用ifdown命令时，禁用的接口用ifconfig命令显示不出来，且显示中没有UP选项，如果想要展示要指定接口或者使用-a选项。
CentOS 7：在使用ifdown命令禁用网卡UP选项不会消失，但是IP没有显示
# ifdown eno33554984 Device 'eno33554984' successfully disconnected. eno33554984: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether 00:0c:29:8e:1d:fd txqueuelen 1000 (Ethernet) RX packets 3763 bytes 291395 (284.5 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 191 bytes 21542 (21.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 # ifup eno33554984 eno33554984: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 172.18.100.109 netmask 255.255.0.0 broadcast 172.18.255.255 inet6 fe80::20c:29ff:fe8e:1dfd prefixlen 64 scopeid 0x20<link> ether 00:0c:29:8e:1d:fd txqueuelen 1000 (Ethernet) RX packets 3863 bytes 298512 (291.5 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 200 bytes 22508 (21.9 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
六：配置主机名：
hostname命令：
查看：hostname
配置：hostnem HOSTNAME
立即生效，重启后无效
# hostname localhost.localdomain # hostname haha # hostname haha
hostnamectl命令(CentOS 7)
hostnamectl status:显示当前主机名信息
hostnamectl set-hostname：设定主机名，永久有效
# hostnamectl status Static hostname: localhost.localdomain Transient hostname: haha Icon name: computer-vm Chassis: vm Machine ID: 3e995ea5a1f94852bf154b2a70b09756 Boot ID: 6e788705dc6646eea8fbf69c05befe64 Virtualization: vmware Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-327.el7.x86_64 Architecture: x86-64 # hostnamectl set-hostname ws # hostnamectl status Static hostname: ws Icon name: computer-vm Chassis: vm Machine ID: 3e995ea5a1f94852bf154b2a70b09756 Boot ID: 6e788705dc6646eea8fbf69c05befe64 Virtualization: vmware Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-327.el7.x86_64 Architecture: x86-64
配置文件：
CentOS6：/etc/sysconfig/network
HOSTNAME=<HOSTNAME> 永久有效，但不会立即生效
# hostname myserver # cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=ws # hostname myserver
CentOS7：/etc/hostname
永久有效，但不会立即生效
# cat /etc/hostname wsssssssssssss # hostnamectl status Static hostname: wsssssssssssss Icon name: computer-vm Chassis: vm Machine ID: 3e995ea5a1f94852bf154b2a70b09756 Boot ID: 6e788705dc6646eea8fbf69c05befe64 Virtualization: vmware Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 3.10.0-327.el7.x86_64 Architecture: x86-64
七：配置DNS服务器指向：
配置文件：/etc/resolv.conf
nameserver DNS_SERVER_IP
# cat /etc/resolv.conf # Generated by NetworkManager nameserver 202.96.199.133 nameserver 8.8.8.8 nameserver 223.5.5.5
八：iproute家族配置管理
(1)ip命令
1> ip link set 改变设备属性
# ip link set eno33554984 down # ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff 3: eno33554984: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:fd brd ff:ff:ff:ff:ff:ff # ip link set eno33554984 up # ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff 3: eno33554984: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:fd brd ff:ff:ff:ff:ff:ff
2> 启用或禁用多播功能：
multicast on 或multicast off
3>重命名接口
# ip link set eno33554984 down # ip link set eno33554984 name eno666777888 # ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff 3: eno666777888: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:fd brd ff:ff:ff:ff:ff:ff
注意：改名时需要先关闭网卡设备
4> 设置mtu大小，默认为1500
# ip link set eno666777888 mtu 1000 # ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff 3: eno666777888: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:fd brd ff:ff:ff:ff:ff:ff
5> ip link show 列出设备属性
# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff 3: eno666777888: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:fd brd ff:ff:ff:ff:ff:ff
(2)ip netns (仅适用于CentOS 7)
ip netns list: 列出所有的netns # ip netns list myspace ip netns add NAME: 创建指定的netns # ip netns add space1 # ip netns list space1 myspace ip netns del NAME: 删除指定的netns # ip netns del myspace [root@localhost ~]# ip netns show space1 ip netns exec NAME COMMAND: 在指定的netns中运行命令 # ip link set eno666777888 netns space1 [root@localhost ~]# ip link show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:0c:29:8e:1d:f3 brd ff:ff:ff:ff:ff:ff # 将某网卡加入到名称空间后 使用IP link show查看，eno666777888已经被隐藏
(3)ip address协议地址管理
ip addr add：添加新的协议地址
[label name]:为额外添加的地址指明接口别名
# ip addr add 10.0.0.100/8 dev eno33554984 label eno33554984:0
ip addr del：删除端口别名
# ip addr del 10.0.0.100/8 dev eno33554984
ip addr show：查看协议地址
# ip addr show
ip addr flush：清除协议地址(清除某设备上的所有地址)
# ip addr flush # ip addr flush eno33554984
(4)ip route路由表管理
ip route add: 添加新的路由
# ip route add 172.18.100.111/24 via 172.18.64.1 dev eno33554984 # ip route default via 10.0.0.254 dev eno16777736 proto static metric 100 default via 172.18.0.1 dev eno33554984 proto static metric 101 10.0.0.0/8 dev eno16777736 proto kernel scope link src 10.0.0.8 metric 100 172.18.0.0/16 dev eno33554984 proto kernel scope link src 172.18.100.109 metric 100 172.18.100.111 via 172.18.64.1 dev eno33554984
ip route change：修改理由
# ip route change 172.18.100.111/24 via 172.18.64.2 dev eno33554984 # ip route default via 10.0.0.254 dev eno16777736 proto static metric 100 default via 172.18.0.1 dev eno33554984 proto static metric 101 10.0.0.0/8 dev eno16777736 proto kernel scope link src 10.0.0.8 metric 100 172.18.0.0/16 dev eno33554984 proto kernel scope link src 172.18.100.109 metric 100 172.18.100.111 via 172.18.64.2 dev eno33554984
ip route relace：改变或添加新的路由(如果没有就新添加)
ip route delete：删除路由
# ip route del 172.18.100.111/24 # ip route default via 10.0.0.254 dev eno16777736 proto static metric 100 default via 172.18.0.1 dev eno33554984 proto static metric 101 10.0.0.0/8 dev eno16777736 proto kernel scope link src 10.0.0.8 metric 100 172.18.0.0/16 dev eno33554984 proto kernel scope link src 172.18.100.109 metric 100
ip route get：查看一条路由
# ip route get 172.18.100.111/24
(5) ss 命令
用法与netstat相同
ss [option] [Filter]
选项：
-t:TCP协议相关连接
-u:UDP相关链接
-w:raw socket相关链接
-l:监听状态的链接
-a:所有状态的链接
-n:数字格式
-p:相关程序及PID
-e:扩展格式信息
-m:内存用量
-o:计时器信息
# ss -tan State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* ESTAB 0 52 10.0.0.8:22 10.0.0.1:56452 LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* # ss -uan State Recv-Q Send-Q Local Address:Port Peer Address:Port UNCONN 0 0 *:40478 *:* UNCONN 0 0 *:68 *:* UNCONN 0 0 :::53493 :::*
九：管理网络属性配置文件
(1)网卡配置文件: /etc/sysconfig/network-scripts/ifcfg-IFACE(接口)
命令方式修改：
setup
配置文件修改：
DEVICE=设备名称
BOOTPROTO=激活接口时使用配置的协议属性，有dhcp，static，none
HWADDR=网卡的硬件MAC地址
ONBOOT=是否开机启动 yes 或 no
TYPE=接口类型，常见的有Ethernet、Bridge
IPADDR=IP地址
NETMASK=子网掩码
GATEWAY=网关
DNS1=DNS服务器
UUID=设备的唯一标识
USERCTL=是否允许普通用户控制此设备
PEERDNS=如果BOOTPROTO=dhcp，是否允许dhcp server分配的DNS服务器覆盖本地手动指定的DNS服务器，默认允许
NM-CONTROLLED=是否启用NetworkManager服务控制接口，在centos6中，一般选择禁用，在centos7中启用
示例：CentOS 7
IPV6INIT=yes BOOTPROTO=none DEVICE=eno16777736 ONBOOT=yes UUID=fc03aa9a-32b4-4d25-9576-288a0e3cd39a TYPE=Ethernet DEFROUTE=yes NAME="System eno16777736" PEERDNS=yes IPADDR=172.18.64.1 PREFIX=8 GATEWAY=172.18.0.1 DNS1=202.106.0.20 DNS2=172.18.0.1
示例：CentOS 6
DEVICE=eth0 HWADDR=00:0C:29:69:45:7B TYPE=Ethernet UUID=1e9d304f-319a-4467-ac3c-67159f182f33 ONBOOT=yes NM_CONTROLLED=yes BOOTPROTO=dhcp
(2)路由相关的配置文件：/etc/sysconfig/network-script/route-IFACE
支持两种配置方式，但不可混用：
1>每行一个路由条目
# cat /etc/sysconfig/network-scripts/route-eno33554984 172.0.0.0/8 via 20.0.0.100 # systemctl restart network.service # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.18.0.1 0.0.0.0 UG 100 0 0 eno16777736 0.0.0.0 20.0.0.1 0.0.0.0 UG 101 0 0 eno33554984 20.0.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno33554984 172.0.0.0 20.0.0.100 255.0.0.0 UG 100 0 0 eno33554984 172.18.0.0 0.0.0.0 255.255.0.0 U 100 0 0 eno16777736
2>没三行一个路由条目
# cat /etc/sysconfig/network-scripts/route-eno33554984 ADDRESS0=11.0.0.0 NETMASK0=255.0.0.0 GATEWAY0=20.0.0.100 # systemctl restart network.service # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 172.18.0.1 0.0.0.0 UG 100 0 0 eno16777736 0.0.0.0 20.0.0.1 0.0.0.0 UG 101 0 0 eno33554984 11.0.0.0 20.0.0.100 255.0.0.0 UG 100 0 0 eno33554984 20.0.0.0 0.0.0.0 255.255.255.0 U 100 0 0 eno33554984 172.18.0.0 0.0.0.0 255.255.0.0 U 100 0 0 eno16777736