- All prompts accept 'a' = abort, 'b' = back to previous step - Interface input: validate numeric range and name existence, re-prompt on bad input - IP address: regex check x.x.x.x/prefix format - Gateway: regex check x.x.x.x format - Main loop: 'b' at mode selection goes back to interface list Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>