netns与veth

最新推荐文章于 2025-01-21 22:10:55 发布

marc_chen

最新推荐文章于 2025-01-21 22:10:55 发布

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分类专栏： linux 文章标签：网络 linux 运维

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本文档详细介绍了如何在Linux中创建两个网络命名空间(netns)，然后利用veth pair进行通信。首先创建netns 'ns1' 和 'ns2'，接着创建veth接口，并将其一端分配给每个netns，分别配置IP地址并启动。最后验证veth接口在不同netns间能正常通信。通过这种方法可以实现网络环境的隔离和虚拟化。

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1，创建2个netns
2, 创建1对veth
3,启动veth,并配置ip，veth能够正常通讯
4,将veth的一端移动到其中一个netns中，veth对能正常通讯
5，将veth的另外一端移动到另外一个netns中，veth对能正常通讯

备注：veth pair成对存在，所以一般在宿主机上创建，然后移动到不同的netns中

1，创建2个netns
[root@k8s-node1 ~]# ip netns add ns1
[root@k8s-node1 ~]# ip netns add ns2
[root@k8s-node1 ~]# ip netns list
ns2
ns1

2, 创建1对veth
[root@k8s-node1 ~]# ip link add veth1 type veth peer name veth2

[root@k8s-node1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 00:0c:29:46:24:dd brd ff:ff:ff:ff:ff:ff
inet 192.168.0.61/24 brd 192.168.0.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe46:24dd/64 scope link
valid_lft forever preferred_lft forever
5: veth2@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether d6:c1:44:5a:71:f3 brd ff:ff:ff:ff:ff:ff
6: veth1@veth2: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether 12:42:55:d3:9f:cb brd ff:ff:ff:ff:ff:ff

3,将veth的一端移动到其中一个netns中，配置IP，并启动，veth对能正常通讯
[root@k8s-node1 ~]# ip link set dev veth1 netns ns1
[root@k8s-node1 ~]# ip netns exec ns1 ip address add 172.16.1.10/16 dev veth1
[root@k8s-node1 ~]# ip netns exec ns1 ip link set dev veth1 up
[root@k8s-node1 ~]# ip netns exec ns1 ip a
1: lo: mtu 65536 qdisc noop state DOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
6: veth1@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 12:42:55:d3:9f:cb brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.16.1.10/16 scope global veth1
valid_lft forever preferred_lft forever
inet6 fe80::1042:55ff:fed3:9fcb/64 scope link
valid_lft forever preferred_lft forever
[root@k8s-node1 ~]# ip netns exec ns1 ping 172.16.1.11
PING 172.16.1.11 (172.16.1.11) 56(84) bytes of data.
64 bytes from 172.16.1.11: icmp_seq=1 ttl=64 time=0.060 ms
64 bytes from 172.16.1.11: icmp_seq=2 ttl=64 time=0.398 ms

— 172.16.1.11 ping statistics —
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.060/0.229/0.398/0.169 ms

4，将veth的另外一端移动到另外一个netns中，veth对能正常通讯
[root@k8s-node1 ~]# ip link set dev veth2 netns ns2
[root@k8s-node1 ~]# ip netns exec ns2 ip address add 172.16.1.11/16 dev veth2
[root@k8s-node1 ~]# ip netns exec ns2 ip link set dev veth2 up
[root@k8s-node1 ~]# ip netns exec ns2 ip a
1: lo: mtu 65536 qdisc noop state DOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
5: veth2@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether d6:c1:44:5a:71:f3 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.16.1.11/16 scope global veth2
valid_lft forever preferred_lft forever
inet6 fe80::d4c1:44ff:fe5a:71f3/64 scope link
valid_lft forever preferred_lft forever
[root@k8s-node1 ~]# ip netns exec ns2 ping 172.16.1.10
PING 172.16.1.10 (172.16.1.10) 56(84) bytes of data.
64 bytes from 172.16.1.10: icmp_seq=1 ttl=64 time=0.046 ms
64 bytes from 172.16.1.10: icmp_seq=2 ttl=64 time=0.086 ms
64 bytes from 172.16.1.10: icmp_seq=3 ttl=64 time=0.093 ms

— 172.16.1.10 ping statistics —
3 packets transmitted, 3 received, 0% packet loss, time 2009ms
rtt min/avg/max/mdev = 0.046/0.075/0.093/0.020 ms
[root@k8s-node1 ~]# ip netns exec ns1 ping 172.16.1.11
PING 172.16.1.11 (172.16.1.11) 56(84) bytes of data.
64 bytes from 172.16.1.11: icmp_seq=1 ttl=64 time=0.020 ms
64 bytes from 172.16.1.11: icmp_seq=2 ttl=64 time=0.115 ms

— 172.16.1.11 ping statistics —
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 0.020/0.067/0.115/0.048 ms

备注：
每个网卡的前面有1个编号，且网卡后面也有一个编号，这个是成对存在，所以网卡无论移动到哪里，都可以找得到对应的那个成对的端口
例如：如下2个netns的网卡；编号6和编号5是一对
6: veth1@if5
5: veth2@if6

[root@k8s-node1 ~]# ip netns exec ns1 ip a
1: lo: mtu 65536 qdisc noop state DOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
6: veth1@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 12:42:55:d3:9f:cb brd ff:ff:ff:ff:ff:ff link-netnsid 1
inet 172.16.1.10/16 scope global veth1
valid_lft forever preferred_lft forever
inet6 fe80::1042:55ff:fed3:9fcb/64 scope link
valid_lft forever preferred_lft forever
[root@k8s-node1 ~]# ip netns exec ns2 ip a
1: lo: mtu 65536 qdisc noop state DOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
5: veth2@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether d6:c1:44:5a:71:f3 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.16.1.11/16 scope global veth2
valid_lft forever preferred_lft forever
inet6 fe80::d4c1:44ff:fe5a:71f3/64 scope link
valid_lft forever preferred_lft forever