IPv6 /34 Prefix ReferenceIPv6
A /32 quartered: carve one operator block into four equal slices and each slice is a /34, holding 1,073,741,824 /64 subnets apiece. You will seldom meet one in the wild — this is a knife size for internal carving, not a catalog size for ordering.
/34 facts at a glance
- Total addresses
- 19,807,040,628,566,084,398,385,987,584 (294)
- /64 subnets inside
- 1,073,741,824
- Host/interface bits
- 94
- Example network
- 2001:db8::/34
- First address
- 2001:db8::
- Last address
- 2001:db8:3fff:ffff:ffff:ffff:ffff:ffff
- Typical role
- Regional aggregation block
A /34 in documentation space
Using 2001:db8::/32 (RFC 3849 documentation space) aligned to its own boundary, a /34 occupies:
| Block | First address | Last address |
|---|---|---|
| 2001:db8::/34 | 2001:db8:: | 2001:db8:3fff:ffff:ffff:ffff:ffff:ffff |
How an IPv6 /34 prefix works
A /34 prefix pins the first 34 bits of a 128-bit address, leaving 94 bits free. That free portion holds 294 = 19,807,040,628,566,084,398,385,987,584 distinct addresses, and every such block begins at a multiple of that size. Because each subnet should be a /64, the 30 middle bits between the prefix and the /64 boundary give 1,073,741,824 subnets to hand out.
Where /34 is used
- Splitting a /32 aggregate among regions, products, or tenants.
- Internal partitioning inside large hosting and carrier networks.
- Growth staging: hold three quarters in reserve while one /34 serves active buildout.
Allocation paperwork favors nibble boundaries (multiples of four bits), which is one reason sizes like /34 surface mainly as internal splits rather than official grants.
From a /34 the descent stays round: four /36s, sixteen /38s, sixty-four /40s.
Frequently asked questions
How many addresses does an IPv6 /34 have?
19,807,040,628,566,084,398,385,987,584 — that is 2^94, ninety-four host bits wide.
How many /40s are in a /34?
Sixty-four. Six bits separate the prefixes, so each /34 retails into 64 blocks of /40.
How many /48s fit inside a /34?
16,384. Fourteen bits lie between /34 and the classic site size.
Why does nobody announce a /34?
Mostly convention: registry policy and reverse-DNS delegation both work best on nibble boundaries, so /34s tend to stay hidden inside larger aggregates.
Open this prefix in the calculator
Open 2001:db8::/34 in the IPv6 calculator