LCPE case studies
LCPE · Put your knowledge to work in context.
LCPE is a professional-level networking certification exam structured around six weighted domains: Network Fundamentals (20%), Network Access (20%), IP Connectivity (25%), IP Services (15%), Security Fundamentals (15%), and Automation and Programmability (5%). It is aimed at engineers who already build and troubleshoot routed and switched networks and want formal recognition of that skill, typically people moving from entry-level support into design, implementation, or operations roles. The LCPE case studies are 6 cases and about 4,649 words.
1Single-Stream Replication Crawls on a 1 Gbps WAN Handoff
A candidate is paged about a nightly database replication between a Frankfurt data center and a Singapore warehouse. The provider delivers a 1 Gbps Layer 2 handoff, and ping between the two routers shows a steady 30 ms round trip with no loss.
824 words, about 4 min2DHCP Snooping Trust Breaks a Campus Access Switch
At a 3,000-student campus, access switch SW-A serves 44 ports: 20 PCs in VLAN 10, 20 IP phones in VLAN 30, and 4 lobby ports. The uplink is a single 802.1Q trunk to distribution switch SW-D carrying VLANs 10, 30, and 99; SW-A's management SVI is VLAN 99.
790 words, about 4 min3OSPF Adjacency Flaps Between EXSTART and FULL Across a Pseudowire
HQ-DIST and BR-EDGE are OSPFv2 neighbors over a 50 Mbps provider pseudowire in area 0, subnet 10.12.0.0/30. The adjacency has flapped between FULL and EXSTART roughly every four hours for a week; show ip ospf neighbor sometimes shows EXSTART/EXCHANGE with the dead timer counting down.
759 words, about 4 min4NAT Overload Port Exhaustion and a Second HTTPS Publication
An office has 250 laptops, 40 IP phones, and 30 servers behind one Cisco ISR doing NAT overload to 203.0.113.2/29 (usable .1-.6). The outside interface uses .2 for overload; .3 is statically mapped to a web server at 10.20.0.10; .4 is statically mapped to a mail server; .5 is unused; .6 is the provider gateway.
742 words, about 4 min5ACL Placement and NAT Order of Operations on a Branch Router
A branch router performs NAT overload on Gi0/1 (inside, 10.20.30.0/24) to Gi0/0 (outside, 203.0.113.2). The web server 10.20.30.10 is statically mapped to 203.0.113.5.
734 words, about 4 min6A Netmiko Script Leaves 22 Switches Half-Configured
A managed-services provider supports 60 Cisco Catalyst 9200 switches for one customer. Every Monday a junior engineer runs a Python script that SSHes to each device with Netmiko, enters configuration mode, types vlan 210 , name <name , then interface range Gi1/0/1-12 and switchport access vlan 210 , and finishes with write memory .
800 words, about 4 min