Device Hardening: SSH, AAA & Secure Access

Harden a Cisco IOS router so remote management is allowed only via SSH. You will remove Telnet from the VTY lines, keep local authentication, and add an idle-session timeout. Verify success from a Linux ADMIN host by confirming SSH works and Telnet is refused.

Harden privileged access on a single IOS router by configuring a hashed enable secret, creating a local admin user with privilege 15 and a secret, and enabling service password-encryption. Verify that privileged access requires the secret and that the running-config contains no cleartext passwords.

Harden a single IOS router’s management plane and create tiered CLI access using custom privilege levels. Build two local accounts: a full admin (level 15) and a junior operator (level 5). Elevate only specific exec commands to level 5 so the operator can run them without gaining full configuration rights. Verify behavior from a Linux admin workstation over SSH.

Harden the console and VTY lines on a single Cisco IOS router so idle sessions close automatically and every access path requires authentication. You will configure login local on both console and VTY, set 5-minute exec timeouts, enable logging synchronous on the console, and restrict VTY to SSH. Verification uses show outputs; grading evaluates the deterministic running-config.

Harden the management plane of a single IOS router by throttling brute-force login attempts and presenting a legal-warning banner. You will enable SSH-based management, configure login block-for and delay to resist password-guessing, and verify behavior from an ADMIN Linux workstation.

Harden R1’s management plane by moving SSH login authentication and exec authorization under the IOS AAA framework using the local user database. You will start from a secure SSH-only baseline that still uses login local, enable aaa new-model, define default AAA methods that point at local, and bind VTY lines to AAA. Success is proven by authenticating from the ADMIN host over SSH and landing at the user’s privilege level.

Harden a single Cisco IOS router’s management plane using AAA named method lists applied per-line. Create VTY-AUTH (local then enable) to protect remote SSH access without lockout risk, and CONSOLE-AUTH (local only) to secure the console independently. Verify using show/run sections and test SSH from the ADMIN workstation.

Advanced secure-access capstone, run as a fault hunt. A hardening change was rolled back badly overnight: the edge router is reachable but the management plane is wide open in several different ways at once, and an SSH key cannot even be generated. You get symptoms and the required end state — no fault list. Everything is on one device, so the work is knowing which pieces of a management-plane build depend on each other rather than hunting across a topology.