Hands-on Junos CLI tutorials, OSPF and BGP configuration guides, SRX firewall policies and step-by-step network troubleshooting — lab-tested by working network engineers preparing for JNCIA, JNCIS and beyond.
Latest Guide
OSPF neighbors stuck in ExStart is one of the most common Junos troubleshooting questions on the Juniper community. Most of the time it is an MTU mismatch — here is how to confirm it in 60 seconds and fix every other cause too.
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A working JNCIA-Junos 6-week study plan: lab setup with vSRX/vMX, week-by-week tasks, free Juniper resources, exam strategy and what to memorize vs what to skip.
An EX3400 Virtual Chassis that shows a missing member after a reboot, or splits into two masters, is one of the most-searched EX-series problems. Here is how split-and-merge works and the command path to recover cleanly.
Configure Juniper SRX hub-and-spoke IPSec VPNs to Azure and AWS: IKEv2, route-based VPNs, BGP over IPsec, NAT-Traversal and routing-instance separation.
Every Juniper engineer hits the 'configuration database locked' error eventually. Here is how to find who holds the lock, clear a stale one, and understand exclusive vs private configuration mode.
The Juniper KB and community threads about a reth showing down while its member physical interfaces are up almost always end at LACP or cluster redundancy-group state. Here is the full diagnosis path with the exact show commands.
Master Junos MX Class-of-Service: classifiers, forwarding classes, schedulers, rewrite rules and hierarchical CoS for voice, video and bulk-data traffic shaping.
NAT is the number one SRX problem posted on Reddit and the Juniper forums. This field guide shows how to read show security flow session, verify NAT rule hits, fix proxy-arp and pin down why traffic is silently dropped.
Step-by-step EVPN-VXLAN multi-vendor interop guide for Junos MX/QFX, Cisco Nexus NX-OS and Arista EOS — Type-2/Type-3 routes, BGP address-family and proven troubleshooting.
Junos OS 23.2R1 is out: enhanced EVPN-VXLAN on MX, SRX inline IDS improvements, security advisories fixed in this train and upgrade guidance.