I wanted to share my experience, hope it will work for some other people. I went ahead and got to a point where I could jot down the class C CIDR table like this:
*I don’t think they’ll ask you about a /31, all the questions I got about point-to-point were using /30 but you should know that it could be used as point-to-point for some cases.
Now, looking at this chart is a bit overwhelming, right? But, there’s some really simple things going on here. First off, write down the first column, all the notation (/XX). Then the next column. Starts at 2 and doubles up to 128. Third column? Just the opposite. Start with 2 at the bottom and work your way back up. Third column is just the value of the second column minus two (for available addresses). Subnet mask column is the only one that really requires any math, but it’s still simple–take the value of the previous line’s mask, then you just add the value of the hosts column for the this line (/26 = 128 + 64 = 192).
So there are really only two things that you need to really *know*–A /25 network has 2 networks and is .128. Fill out the headers of your chart like above (Network, Hosts, Available, Mask) and the rest is simple fill-in-by-sequence. At this point, with this method, I can literally slap this chart down in under a minute on paper.
Here are the other resources. First some video collections on subnetting
Practice Subnetting IPv4:
Sunny Classroom – Subnetting Videos
Professor Messer’s Seven Second Subnetting
Network+ N10-007 Performance Based Questions (PBQ) This PBQ was still on the N10-008 when I took the exam
Reddit articles by bobwyzguy
WyzGuys Reference Desk
The refence desk is a collection I put together early in my career, and posted on my website as a quick and easy reference for myself. This has turned out to be one of my most frequently visited pages. There is an extensive section on networking from when I was studying for the CCNA.
One of your PBQs is going to involve configuring and access point. Spend plenty of time getting familiar with the configuration interface. The Linksys E1500 is similar to the GUI on the exam.