ACL App Filter: Permit SSH/HTTP, Block Telnet/ICMP

Bundle lab · $29.99

Build a two-router, one-access-switch lab with a client and a server. Establish basic IP connectivity with static routing, then implement an extended IPv4 ACL inbound on the client-facing interface to permit SSH and HTTP to the server while denying Telnet and ICMP echo. Validate from the client and review ACL hit counters for proof.

Learning objectives

• Design and deploy an extended IPv4 ACL to filter traffic by protocol and TCP/UDP port.
• Place an extended ACL inbound near the source so only client-initiated traffic is filtered.
• Permit SSH (tcp/22) and HTTP (tcp/80) to the server while denying Telnet (tcp/23) and ICMP echo.
• Verify operation with client-side tests and router ACL hit counters.
• Troubleshoot ACL order, placement, and basic IP reachability issues.

Troubleshooting focus

• Verify every link's interface status and IP addressing (`show ip interface brief`) and correct any interface that is down or misaddressed.
• Confirm each device's running configuration matches the lab objective, and bring any interface, route, or service that is not in its expected state back to health.
• Trace end-to-end reachability with ping/traceroute and isolate the first hop where forwarding fails.