$ ~/registry/skill/affaan-m-network-bgp-diagnostics

SKILL

network-bgp-diagnostics

Name: network-bgp-diagnostics
Author: affaan-m

Troubleshoot BGP sessions, routing policy issues, and collect safe diagnostic evidence.

Stars

★ 282,208

Source

GitHub

Updated

2026-10-17

// securityLow risk

Prompt only, no code
Open source
Community-trusted· 282.2k

Running security audit…

Credentials
Network egress
Code execution
Data access
Supply chain

// install

Copy the install command and let the AI configure it · recommended for beginners

Please install the "network-bgp-diagnostics" skill from askskill:
1. Download https://raw.githubusercontent.com/affaan-m/ECC/main/skills/network-bgp-diagnostics/SKILL.md
2. Save it as ~/.claude/skills/network-bgp-diagnostics/SKILL.md
3. Reload skills and tell me it's ready

// download

Download SKILL.mdInstall manifest ↗

// examples

Diagnose neighbor not establishing

Prompt

Provide diagnostics-only BGP troubleshooting steps for a neighbor stuck in Idle, Active, or Connect state. Structure the answer as: which commands to check first, which fields matter in each command, and how to tell whether the issue is peer configuration, link, ASN, authentication, or timer related. Do not include any change commands.

Expected

A read-only troubleshooting checklist covering states, timers, message counters, error clues, and likely root causes.

Check missing received or advertised routes

Prompt

I need a diagnostics-only workflow to determine why a prefix is not being received from a BGP neighbor or why it is not being advertised. Cover checks for prefix-lists, route-maps, communities, next-hop, max-prefix, and address-family settings, and explain what each step helps rule out.

Expected

A diagnostic workflow organized by policy and route propagation path to pinpoint filtering, attribute, or address-family issues.

Inspect AS path and collect evidence

Prompt

Generate a BGP evidence-collection and analysis template for reviewing a route's AS path, local preference, MED, origin, next hop, and best-path selection reasons. Include only safe evidence-gathering commands, guidance for interpreting outputs, and a record template suitable for handing off to a network team.

Expected

A standardized evidence template with read-only commands, key field explanations, and an escalation-friendly record format.

// docs

Network BGP Diagnostics

Use this skill when a BGP session is down, flapping, established with missing routes, or advertising unexpected prefixes. The default workflow is read-only evidence collection; policy and reset actions belong in a reviewed change window.

When to Use

BGP neighbors are stuck in Idle, Connect, Active, OpenSent, or OpenConfirm.
A session is Established but expected prefixes are missing.
A route-map, prefix-list, max-prefix limit, or AS path policy may be filtering routes.
You need before/after evidence for a BGP change.
You are reviewing automation that parses BGP summary output.

Read-Only Triage Flow

Identify the exact neighbor, address family, VRF, and local/remote ASNs.
Capture summary state and last reset reason.
Prove reachability to the peer source address.
Check route policy references before assuming transport failure.
Compare advertised, received, and installed routes where the platform supports those commands.

show bgp summary
show bgp neighbors <peer>
show ip route <peer>
show tcp brief | include <peer>|:179
show logging | include BGP|<peer>
show running-config | section router bgp
show ip prefix-list
show route-map

Use platform-specific address-family commands when the device uses VRFs, IPv6, VPNv4, or EVPN. Do not assume global IPv4 unicast.

State Interpretation

State	First checks
Established with prefix count	Route exchange is up; inspect policy and table selection
Established with zero prefixes	Check inbound policy, max-prefix, advertised routes, and AFI/SAFI
Active	TCP session is not completing; check routing, source, ACLs, and peer reachability
Connect	TCP connection is in progress; check path and remote listener
OpenSent/OpenConfirm	TCP works; check ASN, authentication, timers, capabilities, and logs
Idle	Neighbor may be disabled, missing config, blocked by policy, or backoff timer

Transport Checks

ping <peer> source <local-source>
traceroute <peer> source <local-source>
show ip route <peer>
show bgp neighbors <peer> | include BGP state|Last reset|Local host|Foreign host

If the peer is sourced from a loopback, confirm both directions route to the loopback addresses and that the neighbor config uses the expected update source.

Avoid disabling ACLs or firewall policy as a diagnostic shortcut. Read hit counters, logs, and path state first.

Route Policy Checks

show bgp neighbors <peer> advertised-routes
show bgp neighbors <peer> routes
show ip prefix-list <name>
show route-map <name>
show bgp <prefix>

Some platforms require additional configuration before received-routes is available. Do not add that configuration during incident triage unless the operator approves the change.

AS Path And Prefix Review

show bgp regexp _65001_
show bgp regexp ^65001$
show bgp <prefix>
show bgp neighbors <peer> advertised-routes | include Network|Path|<prefix>

Use AS-path regex carefully. _65001_ matches AS 65001 as a token. Plain 65001 can match longer ASNs or unrelated text.

Parser Pattern

import re
from typing import Any

BGP_SUMMARY_RE = re.compile(
    r"^(?P<neighbor>\d{1,3}(?:\.\d{1,3}){3})\s+"
    r"(?P<version>\d+)\s+"
    r"(?P<remote_as>\d+)\s+"
    r"(?P<msg_rcvd>\d+)\s+"
    r"(?P<msg_sent>\d+)\s+"
    r"(?P<table_version>\d+)\s+"
    r"(?P<input_queue>\d+)\s+"
    r"(?P<output_queue>\d+)\s+"
    r"(?P<uptime>\S+)\s+"
    r"(?P<state_or_prefixes>\S+)$",
    re.M,
)

def parse_bgp_summary(raw: str) -> list[dict[str, Any]]:
    rows = []
    for match in BGP_SUMMARY_RE.finditer(raw):
        state_or_prefixes = match.group("state_or_prefixes")
        if state_or_prefixes.isdigit():
            state = "Established"
            prefixes_received = int(state_or_prefixes)
        else:
            state = state_or_prefixes
            prefixes_received = None
        rows.append({

…

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