pkt

name	pkt
description	Create and edit Cisco Packet Tracer 9.0 `.pkt` files from hybrid natural-language requests and explicit commands. Use this skill for topology generation, VLAN/router-on-a-stick, DHCP, management VLAN, Telnet, wireless/AP-client setup, server services, and existing `.pkt` edits.

Cisco Packet Tracer 9.0 .pkt Hybrid Generator/Editor

This skill targets Packet Tracer 9.0.0.0810 and treats a .pkt file as a single binary blob, not a zip container or folder tree.

The current builder/editor is Cisco-sample-centric:

• installed Packet Tracer sample saves are the primary prototype source
• bundled device templates are the secondary fallback for gaps such as missing device families in Cisco's own saves
• imported external labs are reference-only by default
• curated external donor roots can become donor-eligible after validation, but Cisco local donors still rank first

That is intentional: it avoids the invalid synthetic XML approach that Packet Tracer rejects while still keeping the skill usable when Cisco's own sample set does not cover a device family directly.

The prompt-first architecture now follows a planner/validator/autofix split:

1. intent extraction
2. topology/config planning
3. donor ranking
4. donor-prune mutation
5. compatibility validation

Useful ideas from MCP-Packet-Tracer were adopted only at the architecture level. PTBuilder live deploy and external donor usage were intentionally not adopted.

How .pkt Files Work

For the modern format targeted by this skill, the pipeline is:

1. Build a Packet Tracer XML document rooted at <PACKETTRACER5>
2. qCompress the UTF-8 XML bytes using:
   • 4-byte big-endian uncompressed length
   • raw zlib payload
3. Apply Stage-2 XOR obfuscation
4. Encrypt with Twofish in EAX mode and append the 16-byte authentication tag
5. Apply Stage-1 reverse/XOR obfuscation

The XML includes a <VERSION> value. Compatibility is not guaranteed across Packet Tracer releases, so this skill intentionally targets the 9.0 line.

Workflow

1. Parse the request into a hybrid intent plan:
   • topology, device models, links, cable types, ports
   • natural Azerbaijani or mixed-language counts such as 3 dene switch ve 6 komputer
   • department/campus prompts such as 6 sobeli kampus sebekesi
   • VLAN/trunk/access/router-on-a-stick intent
   • router DHCP or server DHCP/DNS intent
   • management VLAN / Telnet intent
   • AP SSID/security and wireless client association intent
   • existing .pkt edit operations when a source file is provided
2. Build an intent-first topology/config plan:
   • topology archetype
   • device list
   • port map
   • VLAN/service/config plan
   • assumptions and blocking gaps
3. Rank Cisco local donor candidates with capability, topology, and donor-graph scoring
4. Optionally search/import remote labs, then rank imported labs as curated donors or reference patterns
5. Apply donor-prune mutations on one working Cisco 9.0 donor lab
6. Validate workspace/runtime/scenario compatibility
7. Encode XML into a .pkt blob with scripts/pkt_codec.py
8. Save generated or edited output locally

Open-first rules remain strict:

• multi-source search and scoring is allowed
• final .pkt apply is still single-donor
• when no safe donor exists, return blocking_gaps plus a blueprint_plan

Files

• scripts/pkt_builder.py Builds Packet Tracer XML from a blueprint
• scripts/pkt_codec.py Encodes and decodes the modern .pkt format
• scripts/generate_pkt.py CLI entrypoint for generate/edit/decode/inventory/explain-plan
• scripts/intent_parser.py Hybrid natural-language and mini-DSL parser
• scripts/pkt_editor.py Existing .pkt inventory and mutation engine
• scripts/sample_catalog.py Capability-tagged sample index and reference-pattern loader
• scripts/sample_selector.py Sample ranking by capability, topology, trust level, and prototype eligibility
• scripts/packet_tracer_env.py Resolves Packet Tracer install, saves root, and executable paths
• scripts/runtime_doctor.py Unified runtime diagnostics for host OS, donor, Packet Tracer paths, and Twofish readiness
• templates/pt900/base_empty.xml Base Packet Tracer 9.0 skeleton
• templates/pt900/device_library/*.xml Secondary fallback device XML templates for the first supported device set

The runtime builder currently prefers the installed FTP sample from the local Packet Tracer saves/ directory. The exact path is resolved at runtime from the local Packet Tracer installation or the PACKET_TRACER_* environment variables.

Prompt-driven donor-prune generation prefers an explicit PACKET_TRACER_COMPAT_DONOR, but it can also auto-detect a working local Packet Tracer 9.0 donor from common local locations when the environment override is absent.

Strict compatibility rules:

• keep PACKET_TRACER_TARGET_VERSION on 9.0.0.0810
• do not downgrade prompt generation to 5.3.0.0011
• do not use a legacy 5.3 donor/template fallback to bypass strict 9.0 mode
• if the donor is missing, undecodable, or version-mismatched, stop with a blocking error instead of switching versions
• if PACKET_TRACER_COMPAT_DONOR is explicitly set and wrong, do not silently fall back to another donor
• every host process must inherit the same PACKET_TRACER_* and PKT_TWOFISH_LIBRARY environment variables; this is not host-specific

Supported First Iteration

• Router, Switch, PC, Server
• LightWeightAccessPoint / WirelessRouter where sample prototypes exist
• natural prompt planning for device counts, VLAN IDs, gig uplinks, fa host links, department/campus prompts, and default chain / core switch topologies
• structured blocking_gaps, assumptions_used, and confidence_score reporting
• transparent explain-plan output with:
  • intent_plan
  • topology_plan
  • config_plan
  • estimate_plan
  • preflight_validation
  • autofix_summary
  • cisco_sample_candidates
  • curated_external_donor_candidates
  • external_reference_patterns
  • validation_report
• explicit port-to-port and cable/media mapping
• VLAN create, access port, trunk port, native VLAN
• router subinterfaces and router-on-a-stick
• named ACL create, permit/deny rule injection, and ip access-group interface binding
• router DHCP pool
• server DHCP pool, DNS enablement, and DNS records
• HTTP / HTTPS / FTP / TFTP / NTP service enable state
• end-device DNS client settings
• management VLAN SVI + default gateway
• Telnet enablement on switches/routers via config mutations
• wireless SSID/security/channel mutations
• wireless client association and DHCP/static mode where compatible prototypes exist
• existing .pkt inventory and edit flow

Defaults

If the user does not specify details:

• Packet Tracer version: 9.0.0.0810
• Subnet: 192.168.1.0/24
• Default gateway: 192.168.1.1
• PC addresses: .10, .11, .12, ...
• Layout:
  • router around (400, 140)
  • switch around (400, 280)
  • PCs along the bottom row

Constraints

• This skill currently plans for Packet Tracer 9.0 only
• The builder currently depends on a local Packet Tracer installation with the bundled sample saves present
• The bundled template library is intentionally minimal in v1
• Imported external sample roots are reference-only unless you explicitly promote them
• Prompt generation in the default path is donor-prune based, not full synthetic rebuild
• If VLANs are requested for end hosts but host-to-VLAN distribution is not provided, the skill returns blocking_gaps instead of guessing and generating an unsafe .pkt
• Manual validation in Packet Tracer is still required before claiming a topology is fully compatible with the Cisco application

CLI Examples

Generate from a blueprint file:

python scripts/generate_pkt.py --blueprint examples/blueprint_minimal.json --output output\minimal.pkt

Generate from a hybrid prompt:

python scripts/generate_pkt.py --prompt "6 şöbəli şəbəkə qur, VLAN 10 20 30 40 50 60 və management VLAN 99 yarat" --output output\campus.pkt

Explain the parsed plan before generation:

python scripts/generate_pkt.py --explain-plan "set SW1 vlan 10 name Finance; enable telnet on SW1 username admin password 1234"

Explain a natural Azerbaijani prompt before generation:

python scripts/generate_pkt.py --explain-plan "3 dene switch ve 6 komputer ve 1 router vlanlarda 10,20,30 switchlerin oz aralarinda ve routerle aralarinda gig portuna qosulsun komputerler ise fa portlarla qosulsun"

Inspect curated donor candidates from a local imported lab root:

python scripts/generate_pkt.py --explain-plan "6 şöbəli şəbəkə qur, hər şöbədə 1 switch 1 AP 1 printer 2 PC 2 tablet olsun" --donor-root C:\labs\curated-pkt-donors --reference-root C:\labs\external-pkt-samples

Only external 9.0.0.0810 labs are promoted into the curated donor pool when their workspace validation passes cleanly, or when they are legacy_uuid_physical donors whose only logical warnings are repeated MEM_ADDR mismatch records.

Search GitHub first, then auto-import matching repos into a local cache:

python scripts/generate_pkt.py --explain-plan "6 department campus with vlan dhcp dns ap" --search-remote --remote-provider github --import-cache-root output\remote-cache

Print the aggregated capability matrix:

python scripts/generate_pkt.py --coverage-report
python scripts/generate_pkt.py --coverage-report --device-family "access points"

Inspect an existing .pkt inventory:

python scripts/generate_pkt.py --inventory input\lab.pkt
python scripts/generate_pkt.py --inventory input\lab.pkt --inventory-capabilities

Edit an existing .pkt directly from a prompt:

python scripts/generate_pkt.py --edit input\lab.pkt --prompt "set Wireless Router0 ssid FIN_WIFI security wpa2-psk passphrase fin12345 channel 6 associate PC0 to Wireless Router0 ssid FIN_WIFI dhcp" --output output\edited_lab.pkt --xml-out output\edited_lab.xml
python scripts/generate_pkt.py --edit input\lab.pkt --prompt "enable dns on Server0 set Server0 dns A www.example.local 192.168.10.20 set PC0 dns 192.168.10.20" --output output\edited_services.pkt

Decode a .pkt back to XML for inspection:

python scripts/generate_pkt.py --decode output\minimal.pkt --xml-out output\minimal.xml

Launch Packet Tracer for a smoke open test:

python scripts/generate_pkt.py --validate-open output\minimal.pkt