JNCIS-DC case studies
JNCIS-DC · Put your knowledge to work in context.
JNCIS-DC is the Specialist-level certification in Juniper Networks' Data Center track, positioned between the Associate-level JNCIA-DC and the Professional-level JNCIP-DC within the Juniper Networks Certification Program (JNCP). JNCP describes itself as "a multi-tiered program of written and hands-on lab exams" whose mission is to validate the Juniper skill set among networking professionals, so the Specialist tier signals a step beyond entry-level familiarity with data center networking on Juniper platforms. It suits network engineers, data center operations staff, and pre-sales or support engineers who already hold associate-level grounding and want a credential that demonstrates deeper data center knowledge before pursuing professional or expert status. Candidates should note that Juniper's certification page lists a JNCIS-DC exam update dated 04/24/25 among its recent news; check the official program pages for the current exam blueprint, objectives, and recommended preparation before scheduling. The JNCIS-DC case studies are 5 cases and about 2,508 words.
1Duplicate BUM Traffic After Adding a VLAN to an EVPN Multihomed Server
A four-leaf, two-spine EVPN-VXLAN fabric uses QFX5120-32C leaves and QFX5120-48Y spines. Each leaf has an anycast VTEP address and 2x100G uplinks.
573 words, about 3 min2Large Transfers Stall on a VXLAN Fabric With 9000-Byte Underlay
An eight-leaf, four-spine VXLAN fabric uses an EBGP underlay with four-way ECMP. Servers use 9000-byte MTU and are dual-homed to leaf pairs.
512 words, about 3 min3Apstra Blueprint Deploy Fails After Leaf RMA
Apstra manages 60 QFX5120 switches across three blueprints. A leaf in the production blueprint was RMA'd.
484 words, about 2 min4MC-LAG Blackhole After Adding a VLAN to One Peer
Two QFX5100 switches run MC-LAG with ICCP over a 2x40G inter-chassis link (ICL). Four dual-homed servers use LACP bonds.
498 words, about 2 min5Partial ZTP Failure Across 40 New Switches
Forty new QFX5120-48Y switches are being staged with ZTP. A DHCP relay on the spine points to an ISC DHCP server; option 43 supplies the Junos image name and a configuration file.
441 words, about 2 min