{
  "id": "networking/pppoe-padi-timeout",
  "signature": "PPPoE: PADI timeout, no Access Concentrator responded on interface eth0",
  "signature_zh": "PPPoE：PADI超时，接口eth0上没有接入集中器响应",
  "regex": "PPPoE: PADI timeout, no Access Concentrator responded on interface \\w+",
  "domain": "networking",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "The PPPoE client sent a PPPoE Active Discovery Initiation (PADI) broadcast but received no PADO response from any Access Concentrator, indicating no PPPoE server on the network or a layer-2 issue.",
  "root_cause_type": "generic",
  "root_cause_zh": "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。",
  "versions": [
    {
      "version": "rp-pppoe 3.15",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Linux kernel 5.10",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "OpenWrt 22.03",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "If no AC exists, retrying the same broadcast will still time out; the network must have a PPPoE server.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "PADI is a broadcast and typically not blocked; the issue is usually at the server side or VLAN mismatch.",
      "fail_rate": 0.65,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "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",
      "success_rate": 0.85,
      "how": "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",
      "condition": "",
      "sources": []
    },
    {
      "action": "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",
      "success_rate": 0.8,
      "how": "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",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "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",
    "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"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://datatracker.ietf.org/doc/html/rfc2516",
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.86,
  "fix_success_rate": 0.8,
  "resolvable": "partial",
  "first_seen": "2024-01-05",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}