{
  "id": "networking/dhcp-offer-not-received",
  "signature": "DHCP: No DHCPOFFER received from server 0.0.0.0",
  "signature_zh": "DHCP：未从服务器0.0.0.0收到DHCPOFFER",
  "regex": "No DHCPOFFER received|DHCP.*no offer",
  "domain": "networking",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "The DHCP client sent a DISCOVER broadcast but did not receive any OFFER from the DHCP server within the timeout, typically due to a misconfigured DHCP server, VLAN mismatch, or a switchport configured as an access port instead of trunk.",
  "root_cause_type": "generic",
  "root_cause_zh": "DHCP客户端发送了DISCOVER广播，但在超时时间内未收到任何来自DHCP服务器的OFFER，通常由DHCP服务器配置错误、VLAN不匹配或交换机端口配置为接入端口而非中继端口引起。",
  "versions": [
    {
      "version": "ISC DHCP 4.4.3",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "dnsmasq 2.89",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Windows Server 2022 DHCP",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "This simply re-initiates the same process; if the server is unreachable or misconfigured, the same error will occur.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "This bypasses DHCP entirely but may cause IP conflicts or routing issues if not coordinated with the network admin; it also ignores the root cause of DHCP failure.",
      "fail_rate": 0.5,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "If the server is not reachable due to VLAN or firewall issues, specifying the server IP will not help; the DISCOVER broadcast must still reach the server.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Verify the DHCP server is running and reachable: `sudo tcpdump -i eth0 port 67 or port 68` to check if DISCOVER packets are sent and if OFFER packets are received.",
      "success_rate": 0.85,
      "how": "Verify the DHCP server is running and reachable: `sudo tcpdump -i eth0 port 67 or port 68` to check if DISCOVER packets are sent and if OFFER packets are received.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Ensure the client's switchport is in the correct VLAN: `show vlan brief` on the switch, and set it with `switchport access vlan 10` if needed.",
      "success_rate": 0.9,
      "how": "Ensure the client's switchport is in the correct VLAN: `show vlan brief` on the switch, and set it with `switchport access vlan 10` if needed.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Check for DHCP snooping on the switch: `show ip dhcp snooping` and add an exception for the trusted port if needed: `ip dhcp snooping trust`.",
      "success_rate": 0.8,
      "how": "Check for DHCP snooping on the switch: `show ip dhcp snooping` and add an exception for the trusted port if needed: `ip dhcp snooping trust`.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Verify the DHCP server is running and reachable: `sudo tcpdump -i eth0 port 67 or port 68` to check if DISCOVER packets are sent and if OFFER packets are received.",
    "Ensure the client's switchport is in the correct VLAN: `show vlan brief` on the switch, and set it with `switchport access vlan 10` if needed.",
    "Check for DHCP snooping on the switch: `show ip dhcp snooping` and add an exception for the trusted port if needed: `ip dhcp snooping trust`."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://www.isc.org/dhcp/",
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.84,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2023-09-05",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}