pyATS Network Device Tool

Server & Testbed

• Server script: $PYATS_MCP_SCRIPT
• Testbed: $PYATS_TESTBED_PATH
• Environment variable: PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH

Available Devices

• R1 (devnetsandboxiosxec8k.cisco.com) — Cisco IOS-XE, C8000v/CSR1kv

How to Call Tools

Use the $MCP_CALL protocol handler to invoke MCP tools:

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" TOOL_NAME 'ARGS_JSON'

All 8 Available Tools

1. pyats_list_devices

List all devices in the testbed with their properties: name, alias, type, OS, platform, connection types, credentials summary.

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_list_devices '{}'

Use when: Starting any session — always list devices first to confirm connectivity and inventory.

2. pyats_run_show_command

Execute any show command with automatic Genie structured parsing. Returns parsed JSON when a Genie parser exists, raw text otherwise.

• device_name (string): Target device from testbed
• command (string): Show command — must start with "show"

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"R1","command":"show ip interface brief"}'

Validation rules:

• Must start with "show"
• No pipes (|), redirects (>), or shell characters
• Cannot include: copy, delete, erase, reload, write, configure keywords
• Do NOT use for show running-config or show logging — use the dedicated tools

Commands with Genie parsers (structured JSON output) on IOS-XE:

Routing:

• show ip route / show ip route vrf <name>
• show ip protocols
• show ip bgp / show ip bgp summary / show ip bgp neighbors
• show ip ospf / show ip ospf neighbor / show ip ospf interface / show ip ospf database
• show ip eigrp neighbors / show ip eigrp topology
• show isis neighbors / show isis database
• show ip static route

Interfaces:

• show ip interface brief / show ipv6 interface brief
• show interfaces / show interfaces <name>
• show interfaces status
• show interfaces counters
• show ip interface

L2/Switching:

• show vlan / show vlan brief
• show spanning-tree / show spanning-tree detail
• show mac address-table
• show etherchannel summary

Neighbors:

• show cdp neighbors / show cdp neighbors detail
• show lldp neighbors / show lldp neighbors detail

FHRP:

• show standby / show standby brief
• show vrrp / show vrrp brief

System:

• show version
• show inventory
• show processes cpu / show processes cpu sorted
• show processes memory / show processes memory sorted
• show platform
• show ntp associations / show ntp status
• show snmp
• show clock
• show bootflash
• show license

Security:

• show access-lists / show ip access-lists
• show crypto isakmp sa / show crypto ipsec sa
• show dot1x
• show port-security
• show authentication sessions

QoS:

• show policy-map / show policy-map interface

VRF / MPLS:

• show vrf / show vrf detail
• show mpls forwarding-table
• show mpls ldp neighbor

Other:

• show arp
• show ip nat translations
• show ip dhcp binding
• show track
• show route-map
• show ip prefix-list
• show bfd neighbors
• show flow monitor

3. pyats_configure_device

Apply configuration changes to a device. Automatically enters config mode and exits.

• device_name (string): Target device
• config_commands (list of strings OR multiline string): Configuration lines

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_configure_device '{"device_name":"R1","config_commands":["interface Loopback99","ip address 99.99.99.99 255.255.255.255","description NetClaw-Test","no shutdown"]}'

Rules:

• Do NOT include configure terminal, conf t, or end — the tool handles mode transitions
• DO include exit commands when you need to return to a higher config context
• Preserves indentation for submode commands (route-maps, ACLs, etc.)
• Blocked commands: write erase, erase, reload, delete, format

4. pyats_show_running_config

Retrieve the full running configuration from a device.

• device_name (string): Target device

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_show_running_config '{"device_name":"R1"}'

Use when: Capturing configuration baselines, auditing config, pre/post change verification.

5. pyats_show_logging

Fetch system logs (last 250 entries) from a device.

• device_name (string): Target device

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_show_logging '{"device_name":"R1"}'

Use when: Checking for errors, tracebacks, interface flaps, protocol events after changes.

6. pyats_ping_from_network_device

Execute ping from the network device itself (not from the MCP client).

• device_name (string): Source device
• command (string): Ping command (e.g., ping 8.8.8.8, ping 10.0.0.1 repeat 100 source Loopback0)

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_ping_from_network_device '{"device_name":"R1","command":"ping 8.8.8.8"}'

Returns: Structured JSON with success rate %, RTT stats, packet loss when Genie parsing succeeds.

7. pyats_run_linux_command

Execute shell commands on Linux-based devices in the testbed.

• device_name (string): Linux-capable device
• command (string): Shell command

Use when: The testbed includes Linux hosts (containers, VMs) for system administration tasks.

8. pyats_run_dynamic_test

Execute a complete pyATS AEtest validation script inline. The script runs in a sandboxed environment.

• test_script_content (string): Complete Python AEtest script

bash
PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "${PYATS_PYTHON:-python3} -u $PYATS_MCP_SCRIPT" pyats_run_dynamic_test '{"test_script_content":"import logging\nfrom pyats import aetest\n\nlogger = logging.getLogger(__name__)\n\nTEST_DATA = {\"expected_interfaces\": [\"GigabitEthernet1\", \"Loopback0\"]}\n\nclass InterfaceTest(aetest.Testcase):\n    @aetest.test\n    def verify_interfaces(self):\n        for intf in TEST_DATA[\"expected_interfaces\"]:\n            logger.info(f\"Checking interface: {intf}\")\n            assert intf.startswith(\"Gi\") or intf.startswith(\"Loop\"), f\"Unexpected interface type: {intf}\"\n\nif __name__ == \"__main__\":\n    aetest.main()"}'

Rules:

• Must define TEST_DATA as a Python dict literal (not loaded from file/network)
• Cannot connect to devices (embed all data inline)
• 300-second timeout
• Banned imports: os, sys, subprocess, shutil, socket, pathlib, pickle, yaml, requests, urllib, http, ssl
• Banned functions: __import__(), eval(), exec(), compile(), open(), json.loads()

Use when: Complex pass/fail validation, multi-step assertions, compliance checks on data already collected via show commands.

Alternative: Direct Python pyATS

For operations beyond the 8 MCP tools, use pyATS directly:

python
from pyats.topology import loader
tb = loader.load('$PYATS_TESTBED_PATH')
device = tb.devices['R1']
device.connect(learn_hostname=True, log_stdout=False)
output = device.parse('show ip interface brief')
print(output)
device.disconnect()

Genie Learn (multi-command feature snapshots)

python
from genie.testbed import load
testbed = load('$PYATS_TESTBED_PATH')
dev = testbed.devices['R1']
dev.connect(learn_hostname=True, log_stdout=False)

# Learn returns an OS-agnostic normalized data model
ospf = dev.learn('ospf')       # Neighbors, interfaces, database, areas, LSAs
bgp = dev.learn('bgp')         # Neighbors, address-families, routes, state
intf = dev.learn('interface')   # All interfaces: status, IP, counters, MTU, speed
routing = dev.learn('routing')  # Full routing table from all protocols
platform = dev.learn('platform') # Hardware, modules, images, slots

print(ospf.info)
dev.disconnect()

All 34 learnable features: acl, arp, bgp, config, device, dot1x, eigrp, fdb, hsrp, igmp, interface, isis, lag, lisp, lldp, mcast, mld, msdp, nd, ntp, ospf, pim, platform, prefix_list, rip, route_policy, routing, static_routing, stp, terminal, utils, vlan, vrf, vxlan.

Genie Diff (state comparison)

python
from genie.utils.diff import Diff

# Capture before state
before = dev.learn('ospf')

# ... make changes ...

# Capture after state
after = dev.learn('ospf')

diff = Diff(before.info, after.info)
diff.findDiff()
print(diff)  # Shows + additions and - deletions