Lately, I've been using PT a lot, since it's more stable and feature rich than the Boson CCNP Simulators (I've seen labs where it asks you to execute a specific command, only the sim WON'T LET YOU DO IT.).
For the most part, I've been configuring various network models, and trying to create scalable systems like you would in the real world. It's not a perfect system (no private-vlan support, no VRRP or GLBP support, a Linksys Wifi router instead of a Cisco AP), but it's miles beyond the average sims (GNS3 + real hardware being the exception).
I've run into some puzzling behavior in some of my sims, though:
Etherchannel experiences random failures and interface flapping
Rapid-PVST+ will work across 90% of the links in my trunk links, but 2-3 will stop working randomly.
I used a generic server end-device as a DHCP server for a specific VLAN. I made sure all trunk and access links were setup properly, I even used ip helper-address, but no clients could see the DHCP server. Even though it was on the same vlan and switch. It's ip was in the same subnet as the other devices.
Are these bugs, or anm I misconfiguring it? I've been following the cisco courseware precisely, since I'm prepping for my CCNP. I've also been using this for ROUTE and TSHOOT practice.
Also, I have no idea how to create custom devices in the program. Everytime I try to add a module to a router, it throws and error about the device being powered on. Any tips on how to get around that?