IPv6 /126 Subnet

Four addresses. Used on older point-to-point links before /127 was recommended. Enter any address below to see its /126 block.

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Examples:

IPv6 network

4 addresses

Documentation

Details

First Address
Last Address
Total Addresses
Expanded
Address Entered

Split Into Subnets

2001:db8:abcd:12::/1272001:db8:abcd:12:: – 2001:db8:abcd:12::1
2001:db8:abcd:12::2/1272001:db8:abcd:12::2 – 2001:db8:abcd:12::3

Subnet Calculator

IPv6 /126 at a glance

Prefix/126
Total Addresses4
Host Bits2
Hex Digits Fixed31 and part of the next

An IPv6 /126 fixes the first 126 of 128 bits. That does not fall on a hex-digit boundary, so blocks are harder to read at a glance; nibble-aligned prefixes (multiples of 4) are preferred.

IPv6 has no broadcast address, so every address in the block can be used, but networks with hosts on them should be /64 so SLAAC and neighbour discovery work as designed.

Questions

How many /64s are in a /126?
None: a /126 is smaller than a /64.
How many addresses are in an IPv6 /126?
4.
What size IPv6 block should a hosting provider give each VM?
A /64 per VM is the cleanest: the customer can use any addresses inside it, and abuse handling and reverse DNS work per /64. A single /128 also works but some software expects a /64.

Every address on your network, watched

Frabs maps each IP to the VM that owns it and stops the abuse coming from it, on Proxmox, Virtualizor, VirtFusion and SolusVM.