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
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.
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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.
A repeatable field procedure for diagnosing BGP session flaps on Junos: check state, parse syslog, inspect hold-time expiry vs. transport resets.
How the Juniper SRX security model works: security zones, address books, policies, screen options and source/destination NAT with a full example.