Before you would be beginning to prepare for CCIE Lab certification exam, you should make a list of technologies from the blueprint that Cisco provides for the particular track which you wish to follow, list all the topics and assess your knowledge on each one, and now you have the beginning of a plan.
Next, I would recommend you research where you will find information on each area. This can be one of the most valuable parts of your journey. The nature of the CCIE is to verify your ability to operate at the highest tier of configuration as well as troubleshooting knowledge. The first thing a CCIE must master is about how to find the correct answer. It is impossible to know everything in multifaceted systems but the certification you would be attempting qualifies you for positions that would be often held responsible for minimizing outages and the associated lost revenue that would be occurring during those outages.
First off, put in the time to build your lab. You can host it on a local machine using a VM, or build a server running ESXi or a bare metal install of VIRL. There are tons of instructions out there on how to do these.
With GNS3 and Unetlab, you would be required to supply your own IOS images, so you would need to be able to do that. I know lots of people who use the VIRL IOSv images in GNS3 and EVE, and there are lots of other solutions out there as well. With both of those platforms, you aren't considered to be limited to a node count.
With any of these solutions, I'd suggest having a plan of attack and some workbooks to use along with them, like that provided at the SPOTO Club. I've enrolled in their prep courses and it has helped me quite a lot in becoming a CCIE.
You might not have studied since clearing the written exam back, and you're hoping to take the lab exam very soon. Unless you're putting in 40-50+ hours per week, I would rather think that you're probably shooting far too soon for an attempt. You might have a great mind and know this stuff inside and out, so maybe you could pull it off, but honestly, at least 6-9 months of strictly lab practice before attempting the lab, is required. And if you haven't studied since your written exam, you're going to be reviewing a lot of material unless you would be having an amazing ability to have total recollect of all of the things you studied for the written.
The lab and the written, in my opinion at least, are two separate beasts and require different skills...but you need to have both a solid theoretical and practical knowledge of literally everything on that massive blueprint. I just had my first fail attempt last month on the lab, and I've been studying for over a year straight, usually, 25-35 hours per week and I have also acquired the study dumps from the SPOTO Club, which proved to be quite helpful. I'm not trying to be a downer, but the CCIE is not a piece of cake, which you could just pass in 2 or three months. You are required to put 12-18 months of study time between the written and the lab, and that too without any break, for gaining better results. That's my experience, and probably the experience of a lot of other people who I've talked to while reviewing the SPOTO Club before joining.
So, if you too wish to clear your CCIE Exam in a single attempt, enroll yourself in SPOTO Club Prep Courses.
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