NDP：在eth0上检测到fe80::1的重复地址，重复地址检测失败
NDP: Duplicate address detected for fe80::1 on eth0, DAD failed
ID: networking/ndp-duplicate-address
版本兼容性
| 版本 | 状态 | 引入 | 弃用 | 备注 |
|---|---|---|---|---|
| Linux kernel 6.1.0-17-amd64 | active | — | — | — |
| Windows Server 2022 IPv6 stack | active | — | — | — |
| Cisco IOS 15.9(3)M | active | — | — | — |
| FreeBSD 14.0 | active | — | — | — |
根因分析
IPv6链路本地地址的重复地址检测（DAD）失败，因为同一链路上的另一台主机已在使用该地址，通常是由于手动配置重叠或恶意设备。
English
Duplicate Address Detection (DAD) for an IPv6 link-local address failed because another host on the same link is already using that address, typically due to manual configuration overlap or a rogue device.
官方文档
https://datatracker.ietf.org/doc/html/rfc4862解决方案
-
Manually assign a unique link-local address on the local host: `ip addr add fe80::2/64 dev eth0` and remove the conflicting one
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Identify the conflicting host by scanning the neighbor cache: `ip -6 neigh show dev eth0`, then disconnect or reconfigure it
无效尝试
常见但无效的做法:
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90% 失败
This allows duplicate addresses to persist, causing packet loss and connectivity issues for both hosts.
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70% 失败
The duplicate address is still used by the other host; the local host may get a new address but the conflict is not resolved.
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80% 失败
The duplicate address on the remote host remains; the local host will generate the same address again based on its MAC, leading to the same DAD failure.