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Juniper Networks Certified Associate, Junos (JNCIA-Junos) JN0-106 · Domain 5: Operational monitoring and maintenance

System logging (`/var/log/messages`, `show log`) and protocol traceoptions

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Last reviewed September 25, 2026 · Leer en español

Logs tell you what the device has been doing: interfaces going up and down, commits, logins, routing protocol neighbors changing state and hardware events. Junos writes these to files under /var/log, and the most important one is messages, which is configured by default on most platforms to collect events at notice level and above from all facilities.

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