Today, i went through IEWB Lab 5 as planned. Difficulty rating is 8 out of 10. There were only a few tasks till BGP session. Everything was quite simple till then. Then, things started to get complicated when it reached to VPN session. It was a single AS which is supporting CSC topology to customer carrier. The strange thing is customer carrier CE routers are also peer with a router in another AS which is providing internet service. That was the hard part. Peering was not a problem, but, after peer with that router, routing loops started to form. i had to spend quite a lot of time on that trying to understand what is causing the problem. Finally, create come route maps and putting them here and there solve the problem. Other that that, everything was pretty stright forward and doable.
I have total 5 twelve hours sessions from IE, scheduled in next month as revision before the real lab. I think i could include this lab as one of them.