# ARP：在eth0上未收到192.168.1.50的ARP回复

- **ID:** `networking/arp-request-no-reply`
- **领域:** networking
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

主机发送了针对目标IP地址的ARP请求但未收到回复，表明目标不可达、已关机或位于不同的VLAN/子网中。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| Linux kernel 6.1 | active | — | — |
| Windows 11 22H2 | active | — | — |
| macOS Ventura 13.4 | active | — | — |

## 解决方案

1. ```
   Verify target reachability: ping -c 3 192.168.1.50
   ```
2. ```
   Check ARP table and manually add entry if needed: arp -s 192.168.1.50 00:11:22:33:44:55
   ```

## 无效尝试

- **** — Flushing the ARP cache (arp -d 192.168.1.50) without addressing the underlying connectivity issue only temporarily removes the entry. (85% 失败率)
- **** — Assuming the target is down and rebooting the local machine wastes time if the issue is a VLAN mismatch. (90% 失败率)