#### 1.查看pod的docker容器ID
```bash
$ kubectl get pod -n kube-system nginx-ingress-controller-8489c5b8c4-fccs5 -o json
```
```yaml
...
"containerStatuses": [
{
"containerID": "docker://eda6562ab8d504599016d4dba8ceea4b9b255dbf97446f044ce89ad4410ab49a",
"image": "registry-vpc.cn-shenzhen.aliyuncs.com/acs/aliyun-ingress-controller:v0.44.0.3-8e83e7dc6-aliyun",
"imageID": "docker-pullable://registry-vpc.cn-shenzhen.aliyuncs.com/acs/aliyun-ingress-controller@sha256:7238b6230b678b312113a891ad5f9f7bbedc7839a913eaaee0def8aa748c3313",
"lastState": {
"terminated": {
"containerID": "docker://e9a6d774429c0385be4f3a3129860677a4380277bfe5647563ae4541335111a7",
"exitCode": 255,
"finishedAt": "2021-07-09T06:48:39Z",
"reason": "Error",
"startedAt": "2021-07-08T03:29:36Z"
}
},
"name": "nginx-ingress-controller",
"ready": true,
"restartCount": 1,
"started": true,
"state": {
"running": {
"startedAt": "2021-07-09T06:48:56Z"
}
}
}
],
...
```
#### 2.查看网卡接口索引号
```bash
$ docker exec eda6562ab8d504599016d4dba8ceea4b9b255dbf97446f044ce89ad4410ab49a /bin/bash -c 'cat /sys/class/net/eth0/iflink'
```
```bash
7
```
#### 3.查看网卡接口索引对应的veth网卡
```bash
$ IFLINK_INDEX=7 #IFLINK_INDEX值为上面查询的结果
$ for i in /sys/class/net/veth*/ifindex; do grep -l ^$IFLINK_INDEX$ $i; done
```
```bash
/sys/class/net/vethfe247b7f/ifindex
```
#### 4.tcpdump抓包pod
```bash
$ tcpdump -i vethfe247b7f -nnn
```
```bash
listening on vethfe247b7f, link-type EN10MB (Ethernet), capture size 262144 bytes
18:04:47.362688 IP 100.127.5.192.25291 > 10.151.0.78.80: Flags [S], seq 3419414283, win 2920, options [mss 1460,sackOK,TS val 2630688633 ecr 0,nop,wscale 0], length 0
18:04:47.362704 IP 10.151.0.78.80 > 100.127.5.192.25291: Flags [S.], seq 3153672948, ack 3419414284, win 65535, options [mss 1460,sackOK,TS val 1408463572 ecr 2630688633,nop,wscale 9], length 0
18:04:47.362857 IP 100.127.5.192.25291 > 10.151.0.78.80: Flags [.], ack 1, win 2920, options [nop,nop,TS val 2630688633 ecr 1408463572], length 0
```
