文章目录
Linux 中的网卡
概述
1.网卡在linux中实际上就是用于通信的硬件资源，每一个网卡拥有唯一的MAC地址；
2.网卡实际上是通过文件的形式记录相关的网络配置信息；
查看机器的网卡方式
1.ip a
[root@iZwz91h49n3mj8r232gqweZ ~]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
inet 172.16.252.139/24 brd 172.16.252.255 scope global dynamic eth0
valid_lft 315091224sec preferred_lft 315091224sec
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
link/ether 02:42:7d:a6:c6:8d brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
6: br-d3d1516d3a7c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
link/ether 02:42:62:34:59:56 brd ff:ff:ff:ff:ff:ff
inet 172.18.0.1/16 brd 172.18.255.255 scope global br-d3d1516d3a7c
valid_lft forever preferred_lft forever
8: veth09c86df@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether d2:95:5b:b9:df:58 brd ff:ff:ff:ff:ff:ff link-netnsid 0
10: veth5aaebfd@if9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether de:d7:5a:73:3b:65 brd ff:ff:ff:ff:ff:ff link-netnsid 1
12: vethfa01851@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether e2:94:b6:a5:f6:f5 brd ff:ff:ff:ff:ff:ff link-netnsid 5
14: vethd6d7476@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether 1a:70:f7:4e:66:01 brd ff:ff:ff:ff:ff:ff link-netnsid 2
16: veth2881aeb@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether f6:43:1a:e5:e7:8c brd ff:ff:ff:ff:ff:ff link-netnsid 4
18: vethf151547@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether 9e:f6:a5:ed:09:59 brd ff:ff:ff:ff:ff:ff link-netnsid 3
20: veth0e78003@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether f6:92:4c:29:23:91 brd ff:ff:ff:ff:ff:ff link-netnsid 6
22: vethf7699f4@if21: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether 82:99:f5:a3:ad:b7 brd ff:ff:ff:ff:ff:ff link-netnsid 7
24: vethed86455@if23: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether 66:d0:5f:bf:4f:dd brd ff:ff:ff:ff:ff:ff link-netnsid 8
26: veth9fe54e4@if25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP
link/ether 7e:f0:6f:ef:f7:32 brd ff:ff:ff:ff:ff:ff link-netnsid 9
32: veth1d37c72@if31: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP
link/ether 4e:6a:c7:6f:a1:52 brd ff:ff:ff:ff:ff:ff link-netnsid 10
34: veth6991d55@if33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP
link/ether 9e:24:c9:78:1f:8f brd ff:ff:ff:ff:ff:ff link-netnsid 11
[root@iZwz91h49n3mj8r232gqweZ ~]#
2. ip link show 比较简略版的查看方式
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:7d:a6:c6:8d brd ff:ff:ff:ff:ff:ff
6: br-d3d1516d3a7c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:62:34:59:56 brd ff:ff:ff:ff:ff:ff
8: veth09c86df@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether d2:95:5b:b9:df:58 brd ff:ff:ff:ff:ff:ff link-netnsid 0
10: veth5aaebfd@if9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether de:d7:5a:73:3b:65 brd ff:ff:ff:ff:ff:ff link-netnsid 1
12: vethfa01851@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether e2:94:b6:a5:f6:f5 brd ff:ff:ff:ff:ff:ff link-netnsid 5
14: vethd6d7476@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether 1a:70:f7:4e:66:01 brd ff:ff:ff:ff:ff:ff link-netnsid 2
16: veth2881aeb@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether f6:43:1a:e5:e7:8c brd ff:ff:ff:ff:ff:ff link-netnsid 4
18: vethf151547@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether 9e:f6:a5:ed:09:59 brd ff:ff:ff:ff:ff:ff link-netnsid 3
20: veth0e78003@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether f6:92:4c:29:23:91 brd ff:ff:ff:ff:ff:ff link-netnsid 6
22: vethf7699f4@if21: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether 82:99:f5:a3:ad:b7 brd ff:ff:ff:ff:ff:ff link-netnsid 7
24: vethed86455@if23: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether 66:d0:5f:bf:4f:dd brd ff:ff:ff:ff:ff:ff link-netnsid 8
26: veth9fe54e4@if25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-d3d1516d3a7c state UP mode DEFAULT
link/ether 7e:f0:6f:ef:f7:32 brd ff:ff:ff:ff:ff:ff link-netnsid 9
32: veth1d37c72@if31: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP mode DEFAULT
link/ether 4e:6a:c7:6f:a1:52 brd ff:ff:ff:ff:ff:ff link-netnsid 10
34: veth6991d55@if33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP mode DEFAULT
link/ether 9e:24:c9:78:1f:8f brd ff:ff:ff:ff:ff:ff link-netnsid 11
3.ls /sys/class/net/ -la
[root@iZwz91h49n3mj8r232gqweZ ~]# ls /sys/class/net/ -la
total 0
drwxr-xr-x 2 root root 0 Nov 28 21:55 .
drwxr-xr-x 46 root root 0 Nov 28 21:55 ..
lrwxrwxrwx 1 root root 0 Dec 1 10:39 br-d3d1516d3a7c -> ../../devices/virtual/net/br-d3d1516d3a7c
lrwxrwxrwx 1 root root 0 Dec 1 09:09 docker0 -> ../../devices/virtual/net/docker0
lrwxrwxrwx 1 root root 0 Nov 28 13:55 eth0 -> ../../devices/pci0000:00/0000:00:03.0/virtio0/net/eth0
lrwxrwxrwx 1 root root 0 Nov 28 21:55 lo -> ../../devices/virtual/net/lo
lrwxrwxrwx 1 root root 0 Dec 1 10:39 veth09c86df -> ../../devices/virtual/net/veth09c86df
lrwxrwxrwx 1 root root 0 Dec 1 10:39 veth0e78003 -> ../../devices/virtual/net/veth0e78003
lrwxrwxrwx 1 root root 0 Dec 1 12:46 veth1d37c72 -> ../../devices/virtual/net/veth1d37c72
lrwxrwxrwx 1 root root 0 Dec 1 10:39 veth2881aeb -> ../../devices/virtual/net/veth2881aeb
lrwxrwxrwx 1 root root 0 Dec 1 10:39 veth5aaebfd -> ../../devices/virtual/net/veth5aaebfd
lrwxrwxrwx 1 root root 0 Dec 1 12:49 veth6991d55 -> ../../devices/virtual/net/veth6991d55
lrwxrwxrwx 1 root root 0 Dec 1 10:39 veth9fe54e4 -> ../../devices/virtual/net/veth9fe54e4
lrwxrwxrwx 1 root root 0 Dec 1 10:39 vethd6d7476 -> ../../devices/virtual/net/vethd6d7476
lrwxrwxrwx 1 root root 0 Dec 1 10:39 vethed86455 -> ../../devices/virtual/net/vethed86455
lrwxrwxrwx 1 root root 0 Dec 1 10:39 vethf151547 -> ../../devices/virtual/net/vethf151547
lrwxrwxrwx 1 root root 0 Dec 1 10:39 vethf7699f4 -> ../../devices/virtual/net/vethf7699f4
lrwxrwxrwx 1 root root 0 Dec 1 10:39 vethfa01851 -> ../../devices/virtual/net/vethfa01851
4.ifconfig
[root@iZwz91h49n3mj8r232gqweZ ~]# ifconfig
br-d3d1516d3a7c: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.18.0.1 netmask 255.255.0.0 broadcast 172.18.255.255
ether 02:42:62:34:59:56 txqueuelen 0 (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
docker0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:7d:a6:c6:8d txqueuelen 0 (Ethernet)
RX packets 7750 bytes 407515 (397.9 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 11628 bytes 23845914 (22.7 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.16.252.139 netmask 255.255.255.0 broadcast 172.16.252.255
ether 00:16:3e:0c:ae:fc txqueuelen 1000 (Ethernet)
RX packets 1092231 bytes 1181574745 (1.1 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 657244 bytes 283089043 (269.9 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
loop txqueuelen 1 (Local Loopback)
RX packets 289892 bytes 84866589 (80.9 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 289892 bytes 84866589 (80.9 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth09c86df: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether d2:95:5b:b9:df:58 txqueuelen 0 (Ethernet)
RX packets 15528 bytes 1157565 (1.1 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 15547 bytes 2528543 (2.4 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth0e78003: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether f6:92:4c:29:23:91 txqueuelen 0 (Ethernet)
RX packets 10681 bytes 1323656 (1.2 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7692 bytes 2497248 (2.3 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth1d37c72: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 4e:6a:c7:6f:a1:52 txqueuelen 0 (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
veth2881aeb: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether f6:43:1a:e5:e7:8c txqueuelen 0 (Ethernet)
RX packets 5416 bytes 1847005 (1.7 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5420 bytes 2776343 (2.6 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth5aaebfd: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether de:d7:5a:73:3b:65 txqueuelen 0 (Ethernet)
RX packets 137812 bytes 9730387 (9.2 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 186692 bytes 166006549 (158.3 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
veth6991d55: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 9e:24:c9:78:1f:8f txqueuelen 0 (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
veth9fe54e4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 7e:f0:6f:ef:f7:32 txqueuelen 0 (Ethernet)
RX packets 7783 bytes 2440061 (2.3 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8310 bytes 2591380 (2.4 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethd6d7476: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 1a:70:f7:4e:66:01 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 420 (420.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethed86455: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 66:d0:5f:bf:4f:dd txqueuelen 0 (Ethernet)
RX packets 4607 bytes 2109794 (2.0 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 4568 bytes 441813 (431.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethf151547: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 9e:f6:a5:ed:09:59 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 10 bytes 420 (420.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethf7699f4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 82:99:f5:a3:ad:b7 txqueuelen 0 (Ethernet)
RX packets 182236 bytes 165432726 (157.7 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 135160 bytes 9415715 (8.9 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
vethfa01851: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether e2:94:b6:a5:f6:f5 txqueuelen 0 (Ethernet)
RX packets 3934 bytes 2802594 (2.6 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 5147 bytes 520951 (508.7 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
网卡配置文件
[root@iZwz91h49n3mj8r232gqweZ ~]# cd /etc/sysconfig/network-scripts/
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# ll -la
total 240
drwxr-xr-x. 2 root root 4096 Nov 28 21:55 .
drwxr-xr-x. 6 root root 4096 Nov 28 21:55 ..
-rw------- 1 root root 38 Nov 28 13:55 ifcfg-eth0
-rw-r--r-- 1 root root 254 Sep 12 2016 ifcfg-lo
lrwxrwxrwx 1 root root 24 Aug 18 2017 ifdown -> ../../../usr/sbin/ifdown
-rwxr-xr-x 1 root root 627 Sep 12 2016 ifdown-bnep
-rwxr-xr-x 1 root root 5817 Sep 12 2016 ifdown-eth
-rwxr-xr-x 1 root root 6196 May 26 2017 ifdown-ib
-rwxr-xr-x 1 root root 781 Sep 12 2016 ifdown-ippp
-rwxr-xr-x 1 root root 4201 Sep 12 2016 ifdown-ipv6
lrwxrwxrwx 1 root root 11 Aug 18 2017 ifdown-isdn -> ifdown-ippp
-rwxr-xr-x 1 root root 1778 Sep 12 2016 ifdown-post
-rwxr-xr-x 1 root root 1068 Sep 12 2016 ifdown-ppp
-rwxr-xr-x 1 root root 837 Sep 12 2016 ifdown-routes
-rwxr-xr-x 1 root root 1444 Sep 12 2016 ifdown-sit
-rwxr-xr-x. 1 root root 1621 Nov 6 2016 ifdown-Team
-rwxr-xr-x. 1 root root 1556 Apr 15 2016 ifdown-TeamPort
-rwxr-xr-x 1 root root 1462 Sep 12 2016 ifdown-tunnel
lrwxrwxrwx 1 root root 22 Aug 18 2017 ifup -> ../../../usr/sbin/ifup
-rwxr-xr-x 1 root root 12688 Sep 12 2016 ifup-aliases
-rwxr-xr-x 1 root root 859 Sep 12 2016 ifup-bnep
-rwxr-xr-x 1 root root 11880 Sep 12 2016 ifup-eth
-rwxr-xr-x 1 root root 10145 May 26 2017 ifup-ib
-rwxr-xr-x 1 root root 12039 Sep 12 2016 ifup-ippp
-rwxr-xr-x 1 root root 10525 Sep 12 2016 ifup-ipv6
lrwxrwxrwx 1 root root 9 Aug 18 2017 ifup-isdn -> ifup-ippp
-rwxr-xr-x 1 root root 642 Sep 12 2016 ifup-plip
-rwxr-xr-x 1 root root 1043 Sep 12 2016 ifup-plusb
-rwxr-xr-x 1 root root 2772 Sep 12 2016 ifup-post
-rwxr-xr-x 1 root root 4154 Sep 12 2016 ifup-ppp
-rwxr-xr-x 1 root root 1925 Sep 12 2016 ifup-routes
-rwxr-xr-x 1 root root 3263 Sep 12 2016 ifup-sit
-rwxr-xr-x. 1 root root 1755 Apr 15 2016 ifup-Team
-rwxr-xr-x. 1 root root 1876 Apr 15 2016 ifup-TeamPort
-rwxr-xr-x 1 root root 2682 Sep 12 2016 ifup-tunnel
-rwxr-xr-x 1 root root 1740 Sep 12 2016 ifup-wireless
-rwxr-xr-x 1 root root 4623 Sep 12 2016 init.ipv6-global
-rw-r--r-- 1 root root 15780 Apr 13 2017 network-functions
-rw-r--r-- 1 root root 26829 Sep 12 2016 network-functions-ipv6
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# pwd
/etc/sysconfig/network-scripts
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# vim ifcfg-eth0
内容如下
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
~
解释
1.DEVICE=eth0 网卡的名字是 eth0
2.BOOTPROTO=dhcp 网卡启动类型：dhcp
3.ONBOOT=yes 开机自动启动
4.我们可以通过修改网卡配置文件的形式去修改信息
网卡的IP操作
增加网卡的IP地址
增加之前网卡配置信息
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
inet 172.16.252.139/24 brd 172.16.252.255 scope global dynamic eth0
valid_lft 315089132sec preferred_lft 315089132sec
执行增加网卡命令
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# ip addr add 192.168.0.88 dev eth0
备注
dev 意思device设备，网卡属于硬件
addr 地址
增加之后网卡配置信息
[root@iZwz91h49n3mj8r232gqweZ network-scripts]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
inet 172.16.252.139/24 brd 172.16.252.255 scope global dynamic eth0
valid_lft 315089090sec preferred_lft 315089090sec
inet 192.168.0.88/32 scope global eth0
valid_lft forever preferred_lft forever
删除网卡的IP地址
[root@iZwz91h49n3mj8r232gqweZ ~]# ip addr delete 192.168.0.88/32 dev eth0
[root@iZwz91h49n3mj8r232gqweZ ~]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
inet 172.16.252.139/24 brd 172.16.252.255 scope global dynamic eth0
valid_lft 315088740sec preferred_lft 315088740sec
备注
1.这里注意下192.168.0.88/32，这里注意32是子网掩码
网卡的状态
[root@iZwz91h49n3mj8r232gqweZ ~]# 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
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
inet 172.16.252.139/24 brd 172.16.252.255 scope global dynamic eth0
valid_lft 315088740sec preferred_lft 315088740sec
备注
1.其中里面的state状态 UP即为状态
2.网卡状态有以下几种：
UP
DOWN
NONE
网卡启动 ipup eth0
[root@iZwz91h49n3mj8r232gqweZ ~]# ipup eth0
网卡关闭 ipdown eth0
[root@iZwz91h49n3mj8r232gqweZ ~]# ipdown eth0
网卡的启动和关闭
service network restart
或
systemctl restart network
网卡的分类(分组namespace)和隔离
如何理解网卡的分组
1.一般来讲，一台Nginx服务器，可能有很多网卡，默认实际上是没有分组的，那没有分组，我们可以认为，这些网卡
在分组上都是一组的，也就是默认一组；
2.网络隔离：主要是指的网络资源的隔离 ；
网卡分组操作
插件网卡分组 ip netns list
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns list
增加网卡分组 ip netns add ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns add ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns list
ns1
删除网卡分组 ip netns delete ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns list
ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns delete ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns list
[root@iZwz91h49n3mj8r232gqweZ ~]#
显示网卡分组的ip信息 ip netns exec ns1 ip a 或ip netns exec ns1 ip link show
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
或
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip link show
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
1.这个命令实际上后面跟查看ip的方式是一样的
ip netns exec ns1 + 之前的查看ip的命令如(ip a 或者 ip link show)
2.增加分组之后，会有一个默认的本地lo的网卡
Vitual Ethernet Pair (Veth Pair)
1.成对创建两个网卡，分别可以进行联通
ip link addd veth-ns1 type veth peer name veth-ns2
案例样例
创建成对网卡之前
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:7d:a6:c6:8d brd ff:ff:ff:ff:ff:ff
6: br-d3d1516d3a7c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:62:34:59:56 brd ff:ff:ff:ff:ff:ff
成对创建两个关联的网卡
ip link add veth-ns1 type peer name veth-ns2
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link add veth-ns1 type peer name veth-ns2
Garbage instead of arguments "name ...". Try "ip link help".
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link add veth-ns1 type veth peer name veth-ns2
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:7d:a6:c6:8d brd ff:ff:ff:ff:ff:ff
6: br-d3d1516d3a7c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:62:34:59:56 brd ff:ff:ff:ff:ff:ff
37: veth-ns2@veth-ns1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 1e:db:67:64:ab:1b brd ff:ff:ff:ff:ff:ff
38: veth-ns1@veth-ns2: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether a2:55:52:3e:7e:cd brd ff:ff:ff:ff:ff:ff
设置网卡到指定的network namespace
**派送veth-ns1到ns1 [ip link set veth-ns1 netns ns1] **
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link set veth-ns1 netns ns1
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether 00:16:3e:0c:ae:fc brd ff:ff:ff:ff:ff:ff
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:7d:a6:c6:8d brd ff:ff:ff:ff:ff:ff
6: br-d3d1516d3a7c: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT
link/ether 02:42:62:34:59:56 brd ff:ff:ff:ff:ff:ff
37: veth-ns2@if38: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 1e:db:67:64:ab:1b brd ff:ff:ff:ff:ff:ff link-netnsid 12
[root@iZwz91h49n3mj8r232gqweZ ~]#
1.这里注意下执行派送指定网络分组之后，再次执行ip link show，我们会发现veth-ns1@veth-ns2已经没有了；
2.实际上我们可以这样理解，veth-ns1@veth-ns2 这个之前是在默认的分组(或者是没有分组)里面，现在给指定到ns1分组里面去了,见下面ip netns exec ns1 ip link show
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip link show
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
38: veth-ns1@if37: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether a2:55:52:3e:7e:cd brd ff:ff:ff:ff:ff:ff link-netnsid 0
[root@iZwz91h49n3mj8r232gqweZ ~]#
派送veth-ns2到ns2 [ip link set veth-ns2 netns ns2]
[root@iZwz91h49n3mj8r232gqweZ ~]# ip link set veth-ns2 netns ns2
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
37: veth-ns2@if38: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 1e:db:67:64:ab:1b brd ff:ff:ff:ff:ff:ff link-netnsid 0
这样成对网卡创建完成
设置网卡的ip地址 ip netns exec ns1 ip addr add 192.168.1.10/24 dev veth-ns1
Namespace ns1 增加ip
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip addr add 192.168.1.10/24 dev veth-ns1
[root@iZwz91h49n3mj8r232gqweZ ~]#
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
38: veth-ns1@if37: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether a2:55:52:3e:7e:cd brd ff:ff:ff:ff:ff:ff link-netnsid 1
inet 192.168.1.10/24 scope global veth-ns1
valid_lft forever preferred_lft forever
[root@iZwz91h49n3mj8r232gqweZ ~]#
Namespace ns2 增加ip
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ip addr add 192.168.1.11/24 dev veth-ns2
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
37: veth-ns2@if38: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 1e:db:67:64:ab:1b brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 192.168.1.11/24 scope global veth-ns2
valid_lft forever preferred_lft forever
[root@iZwz91h49n3mj8r232gqweZ ~]#
1.ip netns exec ns1 意思是在ns1这个namespace空间下操作
2.ip addr add 192.168.1.10/24 dev veth-ns1 给网卡 veth-ns1增加ip 192.168.1.10 其中子网掩码是24
3.ip a 查看 会发现 目前已经能够显示我们新增的ip
4.veth-ns2@if38: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN 其中最后一个参数DOWN 标示当前的网卡未生效
将设置的网卡生效
将Namespace下veth-ns1 网卡生效
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip link set veth-ns1 up
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
38: veth-ns1@if37: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state LOWERLAYERDOWN qlen 1000
link/ether a2:55:52:3e:7e:cd brd ff:ff:ff:ff:ff:ff link-netnsid 1
inet 192.168.1.10/24 scope global veth-ns1
valid_lft forever preferred_lft forever
[root@iZwz91h49n3mj8r232gqweZ ~]#
将Namespace下veth-ns2 网卡生效
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ip link set veth-ns2 up
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
37: veth-ns2@if38: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
link/ether 1e:db:67:64:ab:1b brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 192.168.1.11/24 scope global veth-ns2
valid_lft forever preferred_lft forever
inet6 fe80::1cdb:67ff:fe64:ab1b/64 scope link
valid_lft forever preferred_lft forever
[root@iZwz91h49n3mj8r232gqweZ ~]#
备注
1.<NO-CARRIER,BROADCAST,MULTICAST,UP> 其中最后一个参数UP 标示当前的网卡是生效了
测试网卡是否已经生效
在Namespace ns1 下ping Namespace ns2中的ip
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns1 ping 192.168.1.11
PING 192.168.1.11 (192.168.1.11) 56(84) bytes of data.
64 bytes from 192.168.1.11: icmp_seq=1 ttl=64 time=0.067 ms
64 bytes from 192.168.1.11: icmp_seq=2 ttl=64 time=0.047 ms
64 bytes from 192.168.1.11: icmp_seq=3 ttl=64 time=0.048 ms
在Namespace ns2 下ping Namespace ns1中的ip
[root@iZwz91h49n3mj8r232gqweZ ~]# ip netns exec ns2 ping 192.168.1.10
PING 192.168.1.10 (192.168.1.10) 56(84) bytes of data.
64 bytes from 192.168.1.10: icmp_seq=1 ttl=64 time=0.060 ms
64 bytes from 192.168.1.10: icmp_seq=2 ttl=64 time=0.047 ms
64 bytes from 192.168.1.10: icmp_seq=3 ttl=64 time=0.050 ms
^Z
[2]+ Stopped ip netns exec ns2 ping 192.168.1.10
[root@iZwz91h49n3mj8r232gqweZ ~]#
1.能够ping通 说明 两个网络已经生效；这样两个Namespace下的网络能够互相ping通了
如何验证两个网卡是否是成对的（Vitual Ethernet Pair）
安装 bridge-utils 网桥工具（yum install bridge-utils）
[root@iZwz91h49n3mj8r232gqweZ ~]# yum install bridge-utils
Loaded plugins: fastestmirror
base | 3.6 kB 00:00:00
docker-ce-stable | 3.5 kB 00:00:00
epel | 5.4 kB 00:00:00
extras | 2.9 kB 00:00:00
updates | 2.9 kB 00:00:00
(1/3): epel/x86_64/updateinfo | 1.0 MB 00:00:00
(2/3): updates/7/x86_64/primary_db | 5.1 MB 00:00:00
(3/3): epel/x86_64/primary_db | 6.9 MB 00:00:00
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package bridge-utils.x86_64 0:1.5-9.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
===================================================================================================================================================================================================================
Package Arch Version Repository Size
===================================================================================================================================================================================================================
Installing:
bridge-utils x86_64 1.5-9.el7 base 32 k
Transaction Summary
===================================================================================================================================================================================================================
Install 1 Package
Total download size: 32 k
Installed size: 56 k
Is this ok [y/d/N]: y
Downloading packages:
bridge-utils-1.5-9.el7.x86_64.rpm | 32 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : bridge-utils-1.5-9.el7.x86_64 1/1
Verifying : bridge-utils-1.5-9.el7.x86_64 1/1
Installed:
bridge-utils.x86_64 0:1.5-9.el7
Complete!
[root@iZwz91h49n3mj8r232gqweZ ~]#
查看
[root@iZwz91h49n3mj8r232gqweZ ~]# brctl show
bridge name bridge id STP enabled interfaces
br-d3d1516d3a7c 8000.024262345956 no veth09c86df
veth0e78003
veth2881aeb
veth5aaebfd
veth9fe54e4
vethd6d7476
vethed86455
vethf151547
vethf7699f4
vethfa01851
docker0 8000.02427da6c68d no veth20601e8
veth6991d55
[root@iZwz91h49n3mj8r232gqweZ ~]#
1.这里注意下，这里docker0这个网桥下面有下面这些网卡
veth0e78003
veth2881aeb
veth5aaebfd
veth9fe54e4
vethd6d7476
vethed86455
vethf151547
vethf7699f4
vethfa01851
veth20601e8
veth6991d55
