8 hands-on Time Synchronization scenarios you build in your own Cisco Modeling Labs instance and grade against the answer key. Focused Time Synchronization configuration and troubleshooting practice for CCNA and CCNP.
Beginner CCNA NTP lab. Two IOS routers share a single /30 link with no routing. Configure R1 as an authoritative NTP master at stratum 3 and point R2 to R1 as its NTP server. Verify using show ntp associations, show ntp status, and show clock. Emphasis: deterministic config — grading checks the presence of ntp master 3 on R1 and ntp server 10.0.0.1 on R2, not live convergence.
Configure a deterministic NTP broadcast design on a single shared LAN. R1 acts as an authoritative clock (ntp master 3) and broadcasts time on its LAN interface. R2 and R3 act as broadcast clients to scale time distribution without per-client server statements. Verify broadcast associations on the clients and understand the tradeoffs vs. unicast client/server.
Configure a Cisco IOS router as an authoritative NTP master at a chosen stratum and point a neighbor at it as a client. Understand how NTP stratum works and verify deterministically using show commands rather than waiting for live synchronization.
Configure two Cisco IOS routers as symmetric-active NTP peers over a single /30 link. R1 is an authoritative clock (ntp master 4) and both routers form a symmetric peer relationship with ntp peer. Learn how peer mode differs from client/server, and how to verify and troubleshoot associations without relying on Internet sources.
Create a deterministic three-tier NTP hierarchy on a single shared LAN. R1 is the authoritative clock (ntp master 2), R2 syncs to R1, and R3 syncs to R2. No routing or additional subnets — all devices share 10.0.0.0/24 via one L2 switch. Verify with show ntp status and show ntp associations.
Advanced NTP troubleshooting on a two-router /30. R2 never synchronizes its clock. Use show commands to diagnose, then correct the design intent so R2 deterministically references R1, and R1 is an authoritative time source at the agreed stratum. The starter ships with a pre-broken NTP configuration already applied; your job is to find and fix two independent faults.
Build a small LAN with two IOS routers acting as NTP masters at different strata and a client that lists both as time sources, preferring one using the prefer keyword. All routers share a single broadcast domain via a Layer-2 switch, with no routing configured. You will deploy deterministic NTP, verify associations, and understand redundancy selection behavior.
Configure NTP MD5 authentication so a client (R2) synchronizes only to a trusted, authenticated master (R1). R1 is already an authoritative clock (ntp master 3). You will enable NTP authentication on both routers, define and trust key 1, and bind the key on R2's ntp server statement. Verification focuses on authenticated associations and status; actual time lock may take minutes and is not graded.
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