As part of studying for my CCNA Routing and Switching certification, I set up a home lab: a couple of old Cisco routers and a couple more switches, all second-hand from eBay. Let me tell you, if you can afford to do that (my lab came in around $150 with cables and a couple interface cards), or if you can get your job to pay for your lab, there’s nothing quite like actual hands-on time with equipment (and in some ways it’s less hassle setting up real equipment than it is configuring GNS3 properly so it doesn’t eat all your memory).
But.
You may encounter an issue with used equipment. My routers seemed not to hold their configuration between boots, no matter how many times I told it to copy run start.
It would appear that this isn’t that uncommon of a problem, though, and it’s an artifact of the way that eBay sellers wipe equipment before sending it out.
So, if your used router boots to the initial configuration dialog every time, check this out.
On boot, cancel the dialog and enter privileged mode, then run show start. If the startup configuration shown is the same as the configuration you were running when you last shut down your router, check the Configuration Register by running show version. The Configuration Register will probably show 0x2142, which means the router is bypassing the startup config that’s stored in NVRAM, something that’s often invoked during password-recovery.
Fixing this is easy. Enter global configuration mode (conf t) and type config-register 0x2102, then end (or ^Z if, like me, you’re lazy). Another sh ver should now report
Configuration register is 0x2142 (will be 0x2102 at next reload)
Now just reboot your router (reload) and you’re back in business.
Note: if this solution doesn’t work, well, I’m sorry. For a lab environment, any lost configs are just another opportunity to practice, but if you’re using this equipment in a production environment, I hope that you’re backing up your configs. If you’re not backing up your production router and switch configs, check out RANCID, the Really Awesome New Cisco confIg Differ.
Final note: if you’re looking to build your own CCNA practice lab, the setup I’m using is
2x Cisco Catalyst 2950 switches
2x Cisco 2620Xm routers (if you can, the 2621 and 2611 are better than the 2620 and 2610 because they have two built in fastethernet ports rather than only one).
Beep Boop Every Day 