We're Sorry, Full Content Access is for Members Only...

If you like to keep on reading, Become a Member Now! Here is Why:

  • Learn any CCNA, CCNP and CCIE R&S Topic. Explained As Simple As Possible.
  • Try for Just $1. The Best Dollar You've Ever Spent on Your Cisco Career!
  • Full Access to our 617 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)


376 New Members signed up the last 30 days!


100% Satisfaction Guaranteed!
You may cancel your monthly membership at any time.
No Questions Asked!

Forum Replies

  1. Rene, just to be clear, they aren’t the same right?
    2001:41f0:4060:10::/64 and 2001:41f0:4060:A::/64 ?

  2. Rene,
    Greetings from Washington, DC. I have question regarding the IPV6 subnets and hosts. Once I determine my subnets as you describe in the lesson do you simply start counting up to find the valid hosts for that subnet? For example, for the network: 2001:41f0:4060:0001::/64, for the first host on this subnet can I simply put in 2001:41f0:4060:0001::1/64 for the first host on this network?


  3. Hello Willie.

    You got it, that’s exactly right!


  4. Hi I had a question. we are always told no more than 500 IP addresses in a subnet yet here we have 18,446,744,073,709,551,616.00 IP addresses. whats the idea on how this should be handled?

    great IPv6 lesson I’m actually enjoying IPv6 for first time in my studies. in past years I actually cringed learning it now im having fun!

  5. Hello Brian

    Yes, I understand your concern. After spending years (and some of us decades) learning and understanding IPv4 with both its strengths and its limitations, it is very often hard to avoid viewing IPv6 in a similar manner.

    Now if you have a prefix length of 48, 64 or even 96 bits which are all very common in IPv6, then of course you will have a subnet capable of supporting an ridiculously enormous number of hosts. Although IPv6 can actually handle a greater number of hosts per subnet than IPv4 (because there are no broadcasts and because it handles addressing differently) it would not be wise to actually use all those addresses.

    With IPv4, in order to conserve addresses, we subnetted our scopes to sizes comparable to what we need. With IPv6 you don’t need to do that because there are just so many addresses available there is no concern for address exhaustion. So, in order to simplify addressing, just make all your subnets with a /64 prefix and be done with it. Just don’t actually physically place more than 500 devices within a subnet.

    I hope this has been helpful!


20 more replies! Ask a question or join the discussion by visiting our Community Forum