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This episode is the audio from a YouTube video. Some segments reference on-screen demos. Watch the full video at https://youtu.be/dbkwtuXuPPQ
If you’re the senior engineer on a small team, you’re probably being told to put AI agents on your network while being the one who answers for the outage if it goes wrong.
In this episode I build a bounded AI agent with real network tools (FastMCP, Netmiko, Claude Code as the harness, NetBox as the source of truth) and turn it loose on three Cisco IOS XE devices in my CML home lab. It finds a real CVE by checking my running configs against Cisco’s live PSIRT openVuln API, writes the fix, and then my own server-side boundary blocks it from applying anything until I approve the change by name.
What you’ll learn
How to build an MCP server that gives an AI agent real network tools (FastMCP and Netmiko) How to wire it into Claude Code with .mcp.json and keep credentials in shell environment variables, never in config files How to pull live Cisco security advisories through the PSIRT openVuln API and correlate them against your running configs How the agent caught a cross-device ACL gap that neither config shows on its own, then proved it with real packets Why exactly one gated write tool, with everything else read-only, is the shape that makes an agent safe to run How the approval workflow runs: propose, approve by name with a reason, apply, then a full audit log on disk Why a server-side boundary still holds even with every Claude Code permission gate turned off Chapters
00:00 An AI agent found a CVE 01:17 What an AI agent actually is 03:14 Why the boundary matters 06:13 Inside the MCP server 08:59 NetBox, secrets, and wiring it in 13:39 Turn it loose: the audit sweep 15:36 The cross-device ACL gap 18:57 The CVE, honestly scoped 20:21 The boundary says no 21:17 Approve, apply, audit log 24:30 Inside the boundary code 28:03 Skip-permissions test and wrap-up Resources
Hardrails (spec and code front door): https://gtalkstech.com/hardrails Hardrails repo on GitHub: https://github.com/GTalksTech/hardrails Anthropic on trustworthy agents (the “model plus a harness” idea): https://www.anthropic.com/research/trustworthy-agents P.E.N.E. framework by Sif Baksh (a peer working this same problem from the prompt side): https://sifbaksh.com/blog/pene-framework-ai-network-operations/ NetBox: https://github.com/netbox-community NetBox Docker (the source of truth in this episode): https://github.com/netbox-community/netbox-docker Cisco Support APIs: https://developer.cisco.com/site/support-apis/ Cisco PSIRT openVuln API: https://developer.cisco.com/psirt/ CVE-2025-20334 details: https://nvd.nist.gov/vuln/detail/CVE-2025-20334 Netmiko by Kirk Byers: https://github.com/ktbyers/netmiko FastMCP: https://github.com/jlowin/fastmcp Heads up on this one: it’s a screen-share build, so there is real terminal work you can’t see here. The reasoning, the findings, and the boundary argument all stand on their own in audio. If you want to replicate the lab, the video version is worth the watch.
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