# PPPoE：PADI超时，接口eth0上没有接入集中器响应

- **ID:** `networking/pppoe-padi-timeout`
- **领域:** networking
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

PPPoE客户端发送了PPPoE主动发现初始化（PADI）广播，但未收到任何接入集中器的PADO响应，表明网络上没有PPPoE服务器或存在二层问题。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| rp-pppoe 3.15 | active | — | — |
| Linux kernel 5.10 | active | — | — |
| OpenWrt 22.03 | active | — | — |

## 解决方案

1. ```
   Check if the interface is connected to the correct VLAN: ip link show eth0 ; verify VLAN tagging matches the ISP requirement, e.g., vconfig add eth0 10 ; pppoe -I eth0.10
   ```
2. ```
   Run tcpdump to confirm no PADO is received: tcpdump -i eth0 -e -n 'ether proto 0x8863' ; if no packets, contact ISP or check physical connection
   ```

## 无效尝试

- **** — If no AC exists, retrying the same broadcast will still time out; the network must have a PPPoE server. (90% 失败率)
- **** — PADI is a broadcast and typically not blocked; the issue is usually at the server side or VLAN mismatch. (65% 失败率)