JunOS Interface Operations via pyATS

Inspect Juniper device interfaces, link aggregation, class of service, LLDP neighbors, ARP tables, BFD sessions, and optics diagnostics using pyATS pyats_run_show_command. Complements the JunOS MCP server (PyEZ/NETCONF) with SSH/CLI-based operational commands.

How to Call

PYATS_TESTBED_PATH=$PYATS_TESTBED_PATH python3 $MCP_CALL "python3 -u $PYATS_MCP_SCRIPT" pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"<command>"}'

Commands

Interface Status

All Interfaces — Summary

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces terse"}'

Compact table: interface name, admin/oper status, protocol, address. Fastest way to check up/down state across all interfaces.

All Interfaces — Full

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces"}'

Full interface details: physical properties, speed, MTU, MAC, traffic stats, error counters.

All Interfaces — Descriptions

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces descriptions"}'

Interface descriptions only — useful for verifying circuit IDs and peer identifiers. Also: show interfaces descriptions ge-0/0/0.

All Interfaces — Statistics

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces statistics"}'

Input/output bytes, packets, errors, drops across all interfaces. Also: show interfaces statistics ge-0/0/0.

All Interfaces — Extensive

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces extensive"}'

Maximum detail including MAC stats, filter stats, CoS queuing stats, logical interfaces. Also: show interfaces extensive no-forwarding.

Specific Interface

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces ge-0/0/0"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces ge-0/0/0 detail"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces ge-0/0/0 extensive"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces ge-0/0/0 terse"}'

Terse with Match (Filter)

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces terse | match ge-0/0"}'

Filter interface list to a specific FPC/PIC slot.

Interface Policers & Queues

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces policers ge-0/0/0"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces queue ge-0/0/0"}'

Optics Diagnostics

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces diagnostics optics"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show interfaces diagnostics optics ge-0/0/0"}'

SFP/XFP/QSFP optical power levels (tx/rx dBm), laser bias current, temperature, voltage. Critical for detecting failing optics — low rx power indicates fiber or SFP issue.

LACP (Link Aggregation)

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show lacp interfaces ae0"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show lacp statistics interfaces ae0"}'

LACP state, actor/partner system ID, port priority, key, member link status. Statistics show LACP PDU tx/rx counts and errors.

Class of Service

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show class-of-service interface ge-0/0/0"}'

CoS configuration and queue mapping for a specific interface — forwarding class, scheduler, transmit rate.

LLDP Neighbors

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show lldp"}'

LLDP neighbor table — remote system, port, chassis ID. Cross-reference with pyats-topology for neighbor discovery.

ARP Table

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show arp"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show arp no-resolve"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show arp | no-more"}'

ARP cache: MAC address, IP address, interface. no-resolve skips DNS lookups (faster). | no-more disables paging.

IPv6 Neighbors

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show ipv6 neighbors"}'

IPv6 NDP neighbor table — link-layer address, state (reachable/stale/incomplete), interface.

BFD Sessions

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show bfd session"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show bfd session address 10.1.1.2 detail"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show bfd session address 10.1.1.2 extensive"}'
pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"show ppm transmissions protocol bfd detail"}'

BFD session state, interval, multiplier, neighbor. Use for fast-failover validation on OSPF/BGP/LDP sessions.

Traffic Monitoring

pyats_run_show_command '{"device_name":"juniper-rtr-01","command":"monitor interface traffic"}'

Real-time interface traffic rates — bytes/sec, packets/sec per interface. Note: This is a streaming command; pyATS will capture a snapshot.

Workflows

1. JunOS Interface Health Check

show interfaces terse → identify down interfaces
→ show interfaces extensive {down_intf} → error counters, drops
→ show interfaces diagnostics optics {intf} → optical power levels
→ show lldp → verify expected neighbors
→ Severity-sort (down=CRITICAL, errors=WARNING, low optics=WARNING)
→ GAIT

2. LACP Audit

show interfaces terse | match ae → identify LAG interfaces
→ show lacp interfaces {ae_intf} → member status, actor/partner
→ show lacp statistics interfaces {ae_intf} → PDU counters, errors
→ show interfaces {ae_intf} extensive → aggregate stats
→ Flag: missing members, LACP mismatches, PDU errors
→ GAIT

3. Optics Fleet Scan

pyats_list_devices → identify JunOS devices (parallel)
→ show interfaces diagnostics optics per device
→ Flag: rx power < -20 dBm (WARNING), < -25 dBm (CRITICAL)
→ Cross-reference SFP serial numbers with NetBox
→ GAIT

4. ARP/Neighbor Audit

show arp no-resolve → collect ARP table
→ show ipv6 neighbors → collect NDP table
→ Cross-reference with NetBox/Nautobot IPAM → flag unknown MACs
→ show lldp → verify physical neighbors match expected topology
→ GAIT

Integration with Other Skills

Skill	Integration
pyats-junos-system	Chassis/system context for interface issues (FPC/PIC status)
pyats-junos-routing	Routing protocol status complements interface state
junos-network	JunOS MCP for config changes; pyATS for operational verification
pyats-topology	LLDP + ARP data feeds topology discovery
netbox-reconcile	Cross-reference interface IPs, MACs, optics serials with NetBox
pyats-parallel-ops	pCall pattern for fleet-wide interface audits
gait-session-tracking	Every command logged in GAIT

Guardrails

All commands are read-only — show and monitor commands only
No interface config changes — never use set interfaces via this skill
Cross-reference optics — always compare diagnostic values against vendor specifications
Record in GAIT — every command execution must be logged

pyats-junos-interfaces