This week at Null0 Labs, we go hands-on with a real Cisco ASA 5516-X—prepping it for a future project by upgrading the ROMMON, ASA software, and ASDM. Then we dive deep into multi-context mode, turning one physical firewall into two fully isolated virtual firewalls. What’s covered: • ROMMON upgrade for bootloader stability • ASA software & ASDM refresh for modern features • Multi-context mode configuration • Context separation: interfaces, NAT, policies • Real hardware getting ready for deployment 💡 Multi-context mode lets you carve up a single ASA into multiple logical firewalls—perfect for multi-tenant environments or lab segmentation. It’s not just theory—we show it working on real gear. 0:00 Intro 4:05 Device firmware upgrade 11:00 Multi Context Setup 42:15 Outro 🛠️ Stuff I Use 🛠️ EVE-NG - multivendor network emulation software. Linux, Ubuntu, Debian OSX, Windows Networking hardware - Multi vendor 👨🏻‍💻 About Me: Hi I'm Matt a Senior Network Engineer with over two decades of hands-on experience architecting, securing, and optimising high-availability networks across enterprise environments. I stream labs and create video content to help others level up their skills. 💻 Social: Website: [ ]( ) GitHub: [@null0labs]( ) Instagram: [@null0labs]( ) Twitter/X: [@null0labs]( ) LinkedIn:[@mlewisonline]( ) 🙋🏻‍♂️ Questions or ideas? Drop them in the comments. Subscribe for protocol mastery, live labs, and routing realness.