JNCIA-Junos case studies
JNCIA-Junos · Put your knowledge to work in context.
The Juniper Networks Certified Associate – Junos (JNCIA-Junos) is an entry-level certification that verifies you can work confidently in the Junos OS command-line interface and understand the fundamentals of IP networking. It is the usual starting point for network engineers, NOC and operations staff, and anyone who administers Juniper routers, switches, or SRX firewalls, and it also serves as the foundation for Juniper's higher-tier specialist tracks. The JNCIA-Junos case studies are 5 cases and about 3,653 words.
1One-Way Ping After a Server Migration
Two Linux servers were migrated onto the same flat VLAN behind a Junos router. Server A is configured as 172.16.4.10/22 and Server B as 172.16.5.20/24.
714 words, about 4 min2Eight Gigabits Forwarded, Pings to the Router Dropped
A Junos MX-series router forwards about 8 Gbps of transit traffic between two provider handoffs. Over the last 20 minutes, operators report that SSH to the router takes seconds per keystroke, and pings addressed to the router's own ge-0/0/0.0 address show 40% loss and 250 ms latency.
787 words, about 4 min3A Syslog Change That Took Down a Subnet
Router r1 is managed by three engineers, each with an individual login account in the super-user class. At 02:10, Engineer A enters configuration mode to prepare a firewall filter term that will block a decommissioned subnet (10.20.0.0/16).
736 words, about 4 min4A Backup Default Route That Never Activated
Router r1 is dual-homed. ge-0/0/0.0 (203.0.113.1/30) faces ISP-A; ge-0/0/7.0 (198.51.100.1/30) faces ISP-B.
742 words, about 4 min5An Export Policy That Filtered Nothing
r1 is an AS 65000 edge router with an eBGP session to ISP-A (AS 64500) and an iBGP session to r2. The edge team wants r1 to advertise only 198.51.100.0/24 to ISP-A, so they commit: policy-statement TO-ISP { term our-block { from route-filter 198.51.100.0/24 exact; then accept; } } set protocols bgp group ISP-A export TO-ISP After the commit, ISP-A reports it is still receiving 10.0.0.0/16, 192.168.50.0/24 and 198.51.100.0/24 from r1.
674 words, about 3 min