`I have three main buildings with building A with 242 end devices, building B with 54 end devices and building C with 894 device. And all the routers are connected to each other like ring topology. The given IP is FC00:abcd:1234::/48. How can I do the subnetting with given parameters please help me. Topology

Note- the interface between The routers also needed to be subnetted. `

  • 1
    By the way, you cannot use the FC00:abcd:1234::/48 prefix. The first half of ULA, fc00::/8, is Reserved. The second half, fd00::/8, is available for you to use, but you must choose 40 random bits to follow, giving you a relatively unique (remember that the U in ULA means Unique) /48 prefix.
    – Ron Maupin
    Aug 6, 2023 at 20:28

1 Answer 1


Just use a /64 for every network, don't overthink it. And with a /48 you have more than enough /64's to use one for every network and use one /64 to split into /127's for point to point links.

If you use anything other than a /64 on an IPv6 network, some things (like SLAAC) will not work properly.

  • Can you be more specific and give me the full ranges for each network and interface I really need this and this is very imp to me Aug 6, 2023 at 20:02
  • 2
    I'm not here to do your work. If you do not know how to do IPv6 subnet calculation, I suggest you look into that, so you actually understand what you're doing instead of just copy/pasting someone's suggestions.
    – Teun Vink
    Aug 6, 2023 at 20:20
  • 1
    This is starting to feel like a educational/homework question. Please note that these are off topic here.
    – Teun Vink
    Aug 6, 2023 at 20:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.