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.
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FortiGate suits most small offices without Junos skills, SRX suits Junos shops and routing-heavy branches, and Palo Alto suits security-first buyers. This comparison uses published datasheet numbers, explains which throughput row actually matters, and shows how to trial an SRX properly.
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A Junos LACP ae interface that stays down is usually caused by the far end, not the Juniper box. Here is an ordered diagnostic, with root causes ranked by how often we see them, to get from Defaulted or Detached to Collecting distributing.
'Why can't I ping my management interface?' and 'the management interface cannot route' are standing r/Juniper questions. fxp0 on routers, me0 on EX, em0 on SRX — here is how the OOB interface really works and how to configure it right.
'My SRX345 is at 100% CPU' and 'EX switch high CPU' are constant Reddit and Juniper KB topics. Learn to identify rpd, snmpd, httpd and eventd as the culprit process and apply the right fix for each.
NMS dashboards full of 'SNMP timeout' on Juniper gear is a permanent support-checklist item. Juniper's own SNMP troubleshooting checklist covers the causes — polling method, bulk walks, large tables and firewall filtering. Here they are, in field order.
'Input errors are climbing — is it the cable, the optic or the config?' Juniper KB and Reddit threads answer this constantly. Here is every counter in show interfaces extensive explained, with the isolation method that finds the guilty component.
MAC learning storms of invalid addresses, packets flooded out every port, unknown-unicast floods — the Juniper community sees this EX-series problem weekly. The causes are usually one of four: a loop, silent P2P failures, asymmetric routing or a leaking device.
Locked out of an EX, SRX or MX because the root password is lost? Here is the official console recovery procedure — loader prompt, boot -s, recovery shell, new password and commit — plus what to do when it fails.
'How do I leak routes between two VRFs, or from a VRF to the global table?' is a standing question on the Juniper community. Rib-groups and instance-import solve different versions of the problem — here is when to use which, with working configs.
Step-by-step EVPN-VXLAN leaf configuration on EX3400 and EX4300 with QFX as spine, including IRB anycast, MAC learning and verification commands.