本章目录
实验环境为centos7.6,网卡为NAT模式
一、查看及测试网络
1.查看网络
(1)ifconfig–查看网络接口信息
ifconfig后不跟选项参数时,将显示当前主机中已启用(活动)的网络接口信息;后跟具体网络接口名称,则显示该网络接口信息。
ifconfig
[root@smtp ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.41 netmask 255.255.255.0 broadcast 20.0.0.255
inet6 fe80::dd3b:df7b:a35c:96b0 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:ed:09:db txqueuelen 1000 (Ethernet)
RX packets 30929 bytes 13143420 (12.5 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10864 bytes 1798968 (1.7 MiB)
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 1000 (Local Loopback)
RX packets 80 bytes 6552 (6.3 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 80 bytes 6552 (6.3 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:e3:5c:19 txqueuelen 1000 (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
ens33为本机真实的物理网卡,lo为回环网卡可用来测试TCP/IP协议是否正常。
ifconfig ens33
[root@smtp ~]# ifconfig ens33
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 20.0.0.41 netmask 255.255.255.0 broadcast 20.0.0.255
inet6 fe80::dd3b:df7b:a35c:96b0 prefixlen 64 scopeid 0x20<link>
ether 00:0c:29:ed:09:db txqueuelen 1000 (Ethernet)
RX packets 30982 bytes 13147290 (12.5 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10881 bytes 1802098 (1.7 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
(2)hostname–查看及修改主机名
hostname命令可用来查看当前主机名或修改主机名,使用此命令修改主机名为临时修改重启后恢复成原来的主机名。
hostname查看主机名
[root@smtp ~]# hostname
smtp
hostname echo 临时修改主机名为
[root@echo ~]# hostname evil
[root@echo ~]# su
[root@evil ~]#
hostnamectl set-hostname 永久修改主机名
[root@evil ~]# hostnamectl set-hostname echo
[root@evil ~]# su
[root@echo ~]#
一般修改配置分为临时修改和永久修改,临时修改大部分通过命令,永久修改生效一般修改配置文件;hostnamectl特殊是通过命令使永久生效
(3)route–查看路由表
route命令用于查看当前主机中的路由表,可跟选项-n表示以数字显示
[root@echo ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default gateway 0.0.0.0 UG 100 0 0 ens33
20.0.0.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
route -n 可使gateway和default变为数字形式