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Guardrail·Cloud & DevOps

Network Config Validation

Pre-deployment checks for router and switch configuration, including dangerous commands, duplicate addresses, subnet overlaps, stale…

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Buy it · $15 Read it before you buy $15 Written by affaan-m · unverified publisher
Context cost
1.9k tokensestimated from the bundle, loaded when it triggers
Bundle
1 file · 7.7 kBtext throughout, nothing executable
Licence
MITpaid listing
Last change
—no release on file
Servers it uses
Noneruns standalone

What it does

Pre-deployment checks for router and switch configuration, including dangerous commands, duplicate addresses, subnet overlaps, stale references, management-plane risk, and IOS-style security hygiene. Use when reviewing a router or switch configuration before deployment.

Installed, it changes the agent in these ways.

What this skill changes about the agent is not written down here yet. The listing was collected from its source, and the description is in its own SKILL.md.

Guardrail

Constrains what the agent is allowed to do.

devops
Filed under

Cloud & DevOps

The skill itself

This is the whole product. A skill is instructions the model reads, so there is nothing behind the listing you cannot see first — the front matter loads with every session, and the body below it loads when the skill triggers.

SKILL.md7.7 kB · 212 lines
--- name: network-config-validation description: Pre-deployment checks for router and switch configuration, including dangerous commands, duplicate addresses, subnet overlaps, stale references, management-plane risk, and IOS-style security hygiene. Use when reviewing a router or switch configuration before deployment. metadata: origin: community ---
8# Network Config Validation
9
10Use this skill to review network configuration before a change window or before
11an automation run touches production devices.
12
13## When to Use
14
15- Reviewing Cisco IOS or IOS-XE style snippets before deployment.
16- Auditing generated config from scripts or templates.
17- Looking for dangerous commands, duplicate IP addresses, or subnet overlaps.
18- Checking whether ACLs, route-maps, prefix-lists, or line policies are referenced
19 but not defined.
20- Building lightweight pre-flight scripts for network automation.
21
22## How It Works
23
24Treat config validation as layered evidence, not as a complete parser. Regex
25checks are useful for pre-flight warnings, but final approval still needs a
26network engineer to review intent, platform syntax, and rollback steps.
27
28Validate in this order:
29
301. Destructive commands.
312. Credential and management-plane exposure.
323. Duplicate addresses and overlapping subnets.
334. Stale references to ACLs, route-maps, prefix-lists, and interfaces.
345. Operational hygiene such as NTP, timestamps, remote logging, and banners.
35
36## Dangerous Command Detection
37
38```python
39import re
40
41DANGEROUS_PATTERNS: list[tuple[re.Pattern[str], str]] = [
42 (re.compile(r"\breload\b", re.I), "reload causes downtime"),
43 (re.compile(r"\berase\s+(startup|nvram|flash)", re.I), "erases persistent storage"),
44 (re.compile(r"\bformat\b", re.I), "formats a device filesystem"),
45 (re.compile(r"\bno\s+router\s+(bgp|ospf|eigrp)\b", re.I), "removes a routing process"),
46 (re.compile(r"\bno\s+interface\s+\S+", re.I), "removes interface configuration"),
47 (re.compile(r"\baaa\s+new-model\b", re.I), "changes authentication behavior"),
48 (re.compile(r"\bcrypto\s+key\s+(zeroize|generate)\b", re.I), "changes device SSH keys"),
49]
50
51def find_dangerous_commands(lines: list[str]) -> list[dict[str, str | int]]:
52 findings = []
53 for line_number, line in enumerate(lines, start=1):
54 stripped = line.strip()
55 for pattern, reason in DANGEROUS_PATTERNS:
56 if pattern.search(stripped):
57 findings.append({
58 "line": line_number,
59 "command": stripped,
60 "reason": reason,
61 })
62 return findings
63```
64
65## Duplicate IPs And Subnet Overlaps
66
67```python
68import ipaddress
69import re
70from collections import Counter
71
72IP_ADDRESS_RE = re.compile(
73 r"^\s*ip address\s+"
74 r"(?P<ip>\d{1,3}(?:\.\d{1,3}){3})\s+"
75 r"(?P<mask>\d{1,3}(?:\.\d{1,3}){3})\b",
76 re.I | re.M,
77)
78
79def extract_interfaces(config: str) -> list[dict[str, str]]:
80 results = []
81 current = None
82 for line in config.splitlines():
83 if line.startswith("interface "):
84 current = line.split(maxsplit=1)[1]
85 continue
86 match = IP_ADDRESS_RE.match(line)
87 if current and match:
88 ip = match.group("ip")
89 mask = match.group("mask")
90 network = ipaddress.ip_interface(f"{ip}/{mask}").network
91 results.append({"interface": current, "ip": ip, "network": str(network)})
92 return results
93
94def find_duplicate_ips(config: str) -> list[str]:
95 ips = [entry["ip"] for entry in extract_interfaces(config)]
96 counts = Counter(ips)
97 return sorted(ip for ip, count in counts.items() if count > 1)
98
99def find_subnet_overlaps(config: str) -> list[tuple[str, str]]:
100 networks = [ipaddress.ip_network(entry["network"]) for entry in extract_interfaces(config)]
101 overlaps = []
102 for index, left in enumerate(networks):
103 for right in networks[index + 1:]:
104 if left.overlaps(right):
105 overlaps.append((str(left), str(right)))
106 return overlaps
107```
108
109## Management-Plane Checks
110
111Parse VTY blocks by section so access-class checks do not spill across unrelated
112lines.
113
114```python
115import re
116
117def iter_blocks(config: str, starts_with: str) -> list[str]:
118 blocks = []
119 current: list[str] = []
120 for line in config.splitlines():
121 if line.startswith(starts_with):
122 if current:
123 blocks.append("\n".join(current))
124 current = [line]
125 continue
126 if current:
127 if line and not line.startswith(" "):
128 blocks.append("\n".join(current))
129 current = []
130 else:
131 current.append(line)
132 if current:
133 blocks.append("\n".join(current))
134 return blocks
135
136def check_vty_blocks(config: str) -> list[str]:
137 issues = []
138 for block in iter_blocks(config, "line vty"):
139 if re.search(r"transport\s+input\s+.*telnet", block, re.I):
140 issues.append("VTY allows Telnet; require SSH only.")
141 if not re.search(r"\baccess-class\s+\S+\s+in\b", block, re.I):
142 issues.append("VTY block has no inbound access-class source restriction.")
143 if not re.search(r"\bexec-timeout\s+\d+\s+\d+\b", block, re.I):
144 issues.append("VTY block has no explicit exec-timeout.")
145 return issues
146```
147
148## Security Hygiene Checks
149
150```python
151SECURITY_PATTERNS = [
152 (re.compile(r"\bsnmp-server community\s+(public|private)\b", re.I),
153 "default SNMP community configured"),
154 (re.compile(r"\bsnmp-server community\s+\S+", re.I),
155 "SNMPv2 community string configured; prefer SNMPv3 authPriv"),
156 (re.compile(r"\bip ssh version 1\b", re.I),
157 "SSH version 1 enabled"),
158 (re.compile(r"\benable password\b", re.I),
159 "enable password is present; use enable secret"),
160 (re.compile(r"\busername\s+\S+\s+password\b", re.I),
161 "local username uses password instead of secret"),
162]
163
164BEST_PRACTICE_PATTERNS = [
165 (re.compile(r"\bntp server\b", re.I), "NTP server"),
166 (re.compile(r"\bservice timestamps\b", re.I), "log timestamps"),
167 (re.compile(r"\blogging\s+\S+", re.I), "logging destination or buffer"),
168 (re.compile(r"\bsnmp-server group\s+\S+\s+v3\s+priv\b", re.I), "SNMPv3 authPriv group"),
169 (re.compile(r"\bbanner\s+(login|motd)\b", re.I), "login banner"),
170]
171
172def check_security(config: str) -> list[str]:
173 return [message for pattern, message in SECURITY_PATTERNS if pattern.search(config)]
174
175def check_missing_hygiene(config: str) -> list[str]:
176 return [
177 f"Missing {description}"
178 for pattern, description in BEST_PRACTICE_PATTERNS
179 if not pattern.search(config)
180 ]
181```
182
183## Examples
184
185### Change-Window Preflight
186
1871. Run dangerous-command checks on the exact snippet to be pasted.
1882. Run duplicate IP and subnet overlap checks against the full candidate config.
1893. Confirm every referenced ACL, route-map, and prefix-list exists.
1904. Confirm rollback commands and out-of-band access before any management-plane
191 change.
192
193### Automation Preflight
194
195Use validation as a blocking gate before Netmiko, NAPALM, Ansible, or vendor API
196automation pushes a generated config. Fail closed on dangerous commands and
197credentials. Warn on best-practice gaps that are outside the change scope.
198
199## Anti-Patterns
200
201- Treating regex validation as a device parser.
202- Applying generated config without a dry-run diff.
203- Recommending SNMPv2 community strings as a monitoring requirement.
204- Checking VTY blocks with regex that can accidentally span unrelated sections.
205- Testing firewall behavior by disabling ACLs instead of reading counters/logs.
206
207## See Also
208
209- Agent: network-config-reviewer
210- Agent: network-troubleshooter
211- Skill: network-interface-health
212
In the file
SKILL.md799 words
Files1
LicenceMIT
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

Skills are not billed by the call. They are paid for in context: every token the instructions occupy is a token your code, your diff and your conversation cannot use. Here is what this one takes and when it takes it.

≈90
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
1,835
on trigger
The instruction body, read only when the skill fires.
0.96%
of a 200k window
Ten skills this size would take about 10% of the window before you open a file.
050k100k150k200k context window

1.9k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Middling. Fine to keep on in a project where you use it weekly, worth unloading in one where you never do.

Servers bill, skills cost

A server charges by the month. A skill charges once per session, in context, and then keeps charging it for as long as the session lives.

Before and after

The same question, put to the same model twice: once as it comes, and once with these instructions loaded.

No worked example has been published for this skill yet.

Adoption
Installsnone yet
Ratingno reviews yet

The procedure it runs

The procedure has not been published here. It is in the skill’s own SKILL.md, which its author has not sent to the marketplace yet.

Prose, not code

These steps are written for a model to follow, not executed by a runtime. It can still be told to skip one, and it will say so when it does.

Servers it uses

None. This skill calls no MCP servers at all.

Everything it needs is in the instructions, so it works in a project with nothing connected — the model reads the file and changes how it works with what it can already reach.

It writes no files and reaches no network. All it changes is how the model reasons and writes.

What it asks for
Writes filesno
Network accessno

Read from the allowed-tools line of this skill’s own SKILL.md. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

Every skill is narrow, and the useful ones say where they stop. These are the jobs this one is the wrong tool for.

What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

1 file, 7.7 kB on disk. A bundle is text throughout: the instructions the model reads, plus the templates it fills in.

  • SKILL.md7.7 kB
What is not in it

No dependencies and nothing executable: a skill is text the agent reads, so the bundle is 1 file you can review in full before installing. The MIT licence covers the templates and examples as well as the instructions.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

$15 once
Network Config Validation · MIT · affaan-m
one-time
Price$15 once
LicenceMIT — the author’s, unchanged by this purchase
Paid throughStripe, once, on the card you add at the checkout
Keeps workingfor good — the files are yours once they are on disk
Updatesevery update its author ships, delivered through this account

You can read the whole bundle before paying — the SKILL.md above is the product, not a preview of it. What the money buys is the delivery: the folder packaged and handed to your machine by key, every update its author ships, and our support if it does not do what this listing says. The terms of use are MIT, set by the author and unchanged by buying it here.

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Claude Desktop
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Gemini CLI.gemini/skills/
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HTTP / API
This release
Versionnot versioned
Publishedno release date on file
Price$15
Referenceaffaan-m/network-config-validation

Versions

Its author publishes no version number, so there is nothing here to pin to: what you install is the folder as it stands today. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

v
  • No earlier releases have been published to the marketplace.
Pinning

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Reviews

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Who can post

Only accounts that have had the skill installed for fourteen days, so a review is written after living with it rather than after reading it. Publishers may reply once.

Who wrote it

AF
affaan-m

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