55 hands-on Cisco IOS scenarios you build in your own Cisco Modeling Labs instance and grade against the answer key. Cisco IOS configuration and troubleshooting practice for CCNA and CCNP.
Implement Port Address Translation (PAT) using a one-address NAT pool so multiple inside hosts share a single public IP. Reuse the same 5-node topology and addressing as the prior lab; convert the pool to a single address and enable overload. Verify simultaneous connectivity from two inside hosts, observe translations and counters, and contrast with prior pool-exhaustion behavior.
Implement and verify interface-based PAT (overload) on a single-edge SOHO router. Inside hosts on 192.168.10.0/24 share the router’s lone public IP (203.0.113.1) on its outside interface. Validate NAT translations, ACL matches, and simultaneous host access, and practice troubleshooting common misconfigurations (inside/outside role reversal, ACL selection errors).
Build an Internet-edge NAT design that reaches beyond the ISP to a real external network. You will configure dynamic PAT (overload) from a private LAN to a public /29 using a NAT pool on the edge router, with the router’s default route already pointing to the ISP. Verify that an inside host can reach a public server across the ISP and that translations, counters, and default routing reflect the expected state.
Advanced CCNA switchport port-security rollout on multiple access ports across two Layer-2 switches with a trunk. You will standardize a consistent edge policy (sticky MAC learning, maximum 1, violation restrict) on all host-facing access ports while leaving the uplink trunk exempt from port-security. Includes a realistic drift on the trunk allow-list and VLAN database to fix before validating end-to-end user VLAN transport. Pure Layer-2: no SVIs or routing.
Configure a standard IPv4 ACL and bind it to the VTY lines on the HQ router so only the dedicated management host can SSH to it. Confirm that regular routed traffic between sites is unaffected, and prove both a permitted and a denied management attempt.
Three-router static-routing lab with two Linux endpoints. An extended IPv4 ACL is intentionally misordered inbound near the source, causing Telnet to be permitted unexpectedly. Learners must observe first-match behavior via hit counters, enable buffered logging to see ACL log entries, and then correct the ACL sequence so Telnet is blocked while SSH and ICMP are permitted. All routers include a complete SSH management plane. The final solution forwards end-to-end and is enterprise-clean.
Dual-router Branch/HQ lab with a branch client and an HQ server. You will apply an extended IPv4 ACL inbound near the source on the Branch LAN to block specific traffic (TCP/80) while permitting others (ICMP), and a standard IPv4 ACL outbound near the destination on the HQ LAN to admit only the approved source. Validate from real hosts, confirm ACL hitcounts, and keep inter-site connectivity via static routes over a /30 transit.