Linux 虚拟网络设备 veth pair

veth pair

一、`veth pair` 是什么

veth pair 全称是 Virtual Ethernet Pair，是一个成对的端口，所有从这对端口一端进入的数据包都将从另一端出来，反之也是一样。

引入 veth pair 是为了在不同的 Network Namespace 直接进行通信，利用它可以直接将两个 Network Namespace 连接起来。

二、通过 `Containerlab` 构建 `veth pair` 网络

使用 Containerlab 模拟 veth pair

a | 网络拓扑文件

# veth.clab.yml
name: veth
topology:
  nodes:
    server1:
      kind: linux
      image: harbor.dayuan1997.com/devops/nettool:0.9
      exec:
      - ip addr add 10.1.5.10/24 dev net0

    server2:
      kind: linux
      image: harbor.dayuan1997.com/devops/nettool:0.9
      exec:
      - ip addr add 10.1.5.11/24 dev net0


  links:
    - endpoints: ["server1:net0", "server2:net0"]

此拓扑会启动两个节点，并使用单个点对点接口相互互连节点

b | 部署服务

# clab deploy -t veth.clab.yml

INFO[0000] Containerlab v0.54.2 started                 
INFO[0000] Parsing & checking topology file: clab.yaml  
INFO[0000] Creating docker network: Name="clab", IPv4Subnet="172.20.20.0/24", IPv6Subnet="2001:172:20:20::/64", MTU=1500 
INFO[0000] Creating lab directory: /root/wcni-kind/network/4-basic-netwotk/4-veth-pair/1-clab-veth-pair/clab-veth 
INFO[0000] Creating container: "server1"                
INFO[0000] Creating container: "server2"                
INFO[0000] Created link: server1:net0 <--> server2:net0 
INFO[0001] Executed command "ip addr add 10.1.5.11/24 dev net0" on the node "server2". stdout: 
INFO[0001] Executed command "ip addr add 10.1.5.10/24 dev net0" on the node "server1". stdout: 
INFO[0001] Adding containerlab host entries to /etc/hosts file 
INFO[0001] Adding ssh config for containerlab nodes     
INFO[0001] 🎉 New containerlab version 0.55.0 is available! Release notes: https://containerlab.dev/rn/0.55/
Run 'containerlab version upgrade' to upgrade or go check other installation options at https://containerlab.dev/install/ 
+---+-------------------+--------------+------------------------------------------+-------+---------+----------------+----------------------+
| # |       Name        | Container ID |                  Image                   | Kind  |  State  |  IPv4 Address  |     IPv6 Address     |
+---+-------------------+--------------+------------------------------------------+-------+---------+----------------+----------------------+
| 1 | clab-veth-server1 | 4068913afebb | harbor.dayuan1997.com/devops/nettool:0.9 | linux | running | 172.20.20.2/24 | 2001:172:20:20::2/64 |
| 2 | clab-veth-server2 | bd0193b46ed6 | harbor.dayuan1997.com/devops/nettool:0.9 | linux | running | 172.20.20.3/24 | 2001:172:20:20::3/64 |
+---+-------------------+--------------+------------------------------------------+-------+---------+----------------+----------------------+

c | 随机查看一个容器网卡信息

# lo clab-veth-server1 ip a l
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
6: eth0@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:14:14:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.20.20.2/24 brd 172.20.20.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2001:172:20:20::2/64 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::42:acff:fe14:1402/64 scope link 
       valid_lft forever preferred_lft forever
## 本端 ID 为 10
10: net0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9500 qdisc noqueue state UP group default 
    link/ether aa:c1:ab:b8:1d:41 brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet 10.1.5.10/24 scope global net0
       valid_lft forever preferred_lft forever
    inet6 fe80::a8c1:abff:feb8:1d41/64 scope link 
       valid_lft forever preferred_lft forever

d | 查看容器 `net0` 网卡的相关信息

确认对端的 veth pair 信息

# lo clab-veth-server1 ethtool -S net0
NIC statistics:
     peer_ifindex: 11
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops: 0

本端 ID 为 10 ，对端 ID 为 11

e | 查看对端服务 `IP` 网卡信息

# lo clab-veth-server2 ip a l
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
8: eth0@if9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:14:14:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.20.20.3/24 brd 172.20.20.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2001:172:20:20::3/64 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::42:acff:fe14:1403/64 scope link 
       valid_lft forever preferred_lft forever
## 本端 ID 为 11
11: net0@if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9500 qdisc noqueue state UP group default 
    link/ether aa:c1:ab:d1:ab:90 brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet 10.1.5.11/24 scope global net0
       valid_lft forever preferred_lft forever
    inet6 fe80::a8c1:abff:fed1:ab90/64 scope link 
       valid_lft forever preferred_lft forever

# lo clab-veth-server2 ethtool -S net0
NIC statistics:
     peer_ifindex: 10
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops: 0

本端 ID 为 11 ，对端 ID 为 10 ，所以 sever1 和 server2 的 net0 网卡互为 veth pair，双方使用 net0 网卡可以进行数据交换

f | 网络测试

# lo clab-veth-server1 ping 10.1.5.10 -I net0
PING 10.1.5.10 (10.1.5.10): 56 data bytes
64 bytes from 10.1.5.10: seq=0 ttl=64 time=0.039 ms
64 bytes from 10.1.5.10: seq=1 ttl=64 time=0.050 ms
64 bytes from 10.1.5.10: seq=2 ttl=64 time=0.047 ms
^C
--- 10.1.5.10 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.039/0.045/0.050 ms

g | 销毁服务

# clab destroy -t veth.clab.yml

三、手动构建 `veth pair` 网络

a | 网络拓扑

b | 配置命令

## 创建名称空间
ip netns add ns1
ip netns add ns2

## 创建 veth pair 网卡
ip link add veth-01 type veth peer name veth-02

## ns1 配置信息
ip link set veth-01 netns ns1
ip netns exec ns1 ip link set veth-01 up
ip netns exec ns1 ip address add 10.1.5.10/24 dev veth-01

## ns2 配置信息
ip link set veth-02 netns ns2
ip netns exec ns2 ip link set veth-02 up
ip netns exec ns2 ip address add 10.1.5.11/24 dev veth-02

在测试服务器上，应用上述命令

c | 查看 `ns1` 名称空间信息

查看 ip 信息

# ip netns exec ns1 bash
ns1 # ip a l
1: lo: <LOOPBACK> 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
13: veth-01@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ba:a9:01:d3:1c:af brd ff:ff:ff:ff:ff:ff link-netns ns2
    inet 10.1.5.10/24 scope global veth-01
       valid_lft forever preferred_lft forever
    inet6 fe80::b8a9:1ff:fed3:1caf/64 scope link 
       valid_lft forever preferred_lft forever

查看网卡信息

ns1 # ethtool -S veth-01
NIC statistics:
     peer_ifindex: 12
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops: 0
root@evescn:~/wcni-kind/network/4-basic-netwotk/4-veth-pair/1-clab-veth-pair# exit
exit

本端 ID 为 13 ，对端 ID 为 12

d | 查看 `ns2` 名称空间信息

查看 ip 信息

# ip netns exec ns2 bash
ns2 # ip a l
1: lo: <LOOPBACK> 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
12: veth-02@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 4a:8b:65:32:41:ca brd ff:ff:ff:ff:ff:ff link-netns ns1
    inet 10.1.5.11/24 scope global veth-02
       valid_lft forever preferred_lft forever
    inet6 fe80::488b:65ff:fe32:41ca/64 scope link 
       valid_lft forever preferred_lft forever

查看网卡信息

ns2 # ethtool -S veth-02
NIC statistics:
     peer_ifindex: 13
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops: 0

本端 ID 为 12 ，对端 ID 为 13

e | 测试网络

ns2 # ping 10.1.5.10
PING 10.1.5.10 (10.1.5.10) 56(84) bytes of data.
64 bytes from 10.1.5.10: icmp_seq=1 ttl=64 time=0.033 ms
64 bytes from 10.1.5.10: icmp_seq=2 ttl=64 time=0.032 ms
^C
--- 10.1.5.10 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1011ms
rtt min/avg/max/mdev = 0.032/0.032/0.033/0.000 ms

f | 回收名称空间

# ip netns del ns1 && ip netns del ns2

四、手动构建网桥网络

a | 网络拓扑

b | 配置命令

## 创建名称空间
ip netns add ns1
ip netns add ns2

## 创建 br0 类型为网桥
ip l a br0 type bridge
ip l s br0 up

## 创建 2对 veth pair 网卡
ip l a int1 type veth peer name br-int1
ip l a int2 type veth peer name br-int2

## ns1 配置信息，网卡 int1 一端插到 ns1，一端插到 br0 网桥
ip l s int1 netns ns1
ip netns exec ns1 ip l s int1 up
ip netns exec ns1 ip a a 10.1.5.10/24 dev int1

## ns2 配置信息，网卡 int2 一端插到 ns2，一端插到 br0 网桥
ip l s int2 netns ns2
ip netns exec ns2 ip l s int2 up
ip netns exec ns2 ip a a 10.1.5.11/24 dev int2

## 网卡 int1 另一端插到 br0 网桥
ip l s br-int1 master br0
ip l s br-int1 up
## 网卡 int2 另一端插到 br0 网桥
ip l s br-int2 master br0
ip l s br-int2 up

在测试服务器上，应用上述命令

c | 查看 `ns1` 名称空间信息

查看 ip 信息

# ip netns exec ns1 bash
ns1 # ip a l
1: lo: <LOOPBACK> 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
16: int1@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 02:e1:98:20:c7:3e brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.1.5.10/24 scope global int1
       valid_lft forever preferred_lft forever
    inet6 fe80::e1:98ff:fe20:c73e/64 scope link 
       valid_lft forever preferred_lft forever

查看网卡信息

ns1 # ethtool -S int1
NIC statistics:
     peer_ifindex: 15
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops: 
ns1 # exit
exit

本端 ID 为 16 ，对端 ID 为 15

d | 查看 `ns2` 名称空间信息

查看 ip 信息

# ip netns exec ns2 bash
ns2 # ip a l
1: lo: <LOOPBACK> 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
18: int2@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 06:b2:aa:92:19:b3 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.1.5.11/24 scope global int2
       valid_lft forever preferred_lft forever
    inet6 fe80::4b2:aaff:fe92:19b3/64 scope link 
       valid_lft forever preferred_lft forever

查看网卡信息

ns2 # ethtool -S int2
NIC statistics:
     peer_ifindex: 17
     rx_queue_0_xdp_packets: 0
     rx_queue_0_xdp_bytes: 0
     rx_queue_0_xdp_drops:

本端 ID 为 18 ，对端 ID 为 17

e | 查看宿主机网络

# ip a l
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 fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:81:cc:3a brd ff:ff:ff:ff:ff:ff
    inet 172.16.94.141/24 brd 172.16.94.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe81:cc3a/64 scope link 
       valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:0f:a2:2e:f6 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
4: br-c1a42599c7fe: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:dd:46:08:c7 brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.1/16 brd 172.18.255.255 scope global br-c1a42599c7fe
       valid_lft forever preferred_lft forever
    inet6 fc00:f853:ccd:e793::1/64 scope global tentative 
       valid_lft forever preferred_lft forever
    inet6 fe80::1/64 scope link tentative 
       valid_lft forever preferred_lft forever
14: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether d6:cd:25:93:c3:a2 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::8c5a:e2ff:feb2:609b/64 scope link 
       valid_lft forever preferred_lft forever
15: br-int1@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 state UP group default qlen 1000
    link/ether d6:cd:25:93:c3:a2 brd ff:ff:ff:ff:ff:ff link-netns ns1
    inet6 fe80::d4cd:25ff:fe93:c3a2/64 scope link 
       valid_lft forever preferred_lft forever
17: br-int2@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 state UP group default qlen 1000
    link/ether e2:af:58:2b:b5:74 brd ff:ff:ff:ff:ff:ff link-netns ns2
    inet6 fe80::e0af:58ff:fe2b:b574/64 scope link 
       valid_lft forever preferred_lft forever

对比 ns1 和 ns2 网卡信息，可以确定以下信息
- ns1 对端 ID 为 15 的网卡为 br-int1
- ns2 对端 ID 为 17 的网卡为 br-int2

br-int1 和 br-int2 网卡都存在 master br0 ，表示他们都连接到 br0 网桥上

f | 测试网络

ns2 # ping 10.1.5.10
PING 10.1.5.10 (10.1.5.10) 56(84) bytes of data.
64 bytes from 10.1.5.10: icmp_seq=1 ttl=64 time=0.045 ms
64 bytes from 10.1.5.10: icmp_seq=2 ttl=64 time=0.060 ms
64 bytes from 10.1.5.10: icmp_seq=3 ttl=64 time=0.057 ms
64 bytes from 10.1.5.10: icmp_seq=4 ttl=64 time=0.051 ms
^C
--- 10.1.5.10 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3055ms
rtt min/avg/max/mdev = 0.045/0.053/0.060/0.005 ms

g | 回收名称空间

# ip netns del ns1 && ip netns del ns2

posted @ 2024-06-15 15:57 evescn 阅读(130) 评论(0) 编辑收藏举报

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evescn

Linux 虚拟网络设备 veth pair

veth pair

一、veth pair 是什么

二、通过 Containerlab 构建 veth pair 网络

a | 网络拓扑文件

b | 部署服务

c | 随机查看一个容器网卡信息

d | 查看容器 net0 网卡的相关信息

e | 查看对端服务 IP 网卡信息

f | 网络测试

g | 销毁服务

三、手动构建 veth pair 网络

a | 网络拓扑

b | 配置命令

c | 查看 ns1 名称空间信息

d | 查看 ns2 名称空间信息

e | 测试网络

f | 回收名称空间

四、手动构建网桥网络

a | 网络拓扑

b | 配置命令

c | 查看 ns1 名称空间信息

d | 查看 ns2 名称空间信息

e | 查看宿主机网络

f | 测试网络

g | 回收名称空间

公告

一、`veth pair` 是什么

二、通过 `Containerlab` 构建 `veth pair` 网络

d | 查看容器 `net0` 网卡的相关信息

e | 查看对端服务 `IP` 网卡信息

三、手动构建 `veth pair` 网络

c | 查看 `ns1` 名称空间信息

d | 查看 `ns2` 名称空间信息

c | 查看 `ns1` 名称空间信息

d | 查看 `ns2` 名称空间信息