networking network_error ai_generated true

DHCP DECLINE：地址192.168.1.100已在网络上使用

DHCP DECLINE: address 192.168.1.100 already in use on the network

ID: networking/dhcp-address-already-used

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88%修复率
88%置信度
1证据数
2023-11-20首次发现

版本兼容性

版本状态引入弃用备注
ISC DHCP 4.4.3 active — — —
dnsmasq 2.89 active — — —
systemd-networkd 250 active — — —

根因分析

DHCP客户端通过ARP探测发现提供的IP地址已被其他主机使用，因此向服务器发送了DHCPDECLINE。

English

A DHCP client detected via ARP probe that the offered IP address is already in use by another host, so it sent a DHCPDECLINE to the server.

generic

官方文档

https://datatracker.ietf.org/doc/html/rfc2131

解决方案

  1. Identify and remove the conflicting static IP host, then release the address: arp -d 192.168.1.100; dhclient -r eth0; dhclient eth0
  2. Exclude the conflicting address from the DHCP pool in the server config (e.g., in dhcpd.conf: deny 192.168.1.100;)

无效尝试

常见但无效的做法:

  1. 90% 失败

    The conflict is due to a static IP assignment on another host; restarting the server does not resolve the conflicting address.

  2. 95% 失败

    Lease time does not affect address conflicts; the client's ARP probe detects the conflict regardless of lease duration.