IPv6 /52 Prefix ReferenceIPv6
Department-scale delegation: a /52 holds 4,096 /64 subnets — sixteen times a residential /56, one sixteenth of a site /48. This is the tier for buildings, branches, and teams whose VLAN count has outgrown polite conversation.
/52 facts at a glance
- Total addresses
- 75,557,863,725,914,323,419,136 (276)
- /64 subnets inside
- 4,096
- Host/interface bits
- 76
- Example network
- 2001:db8::/52
- First address
- 2001:db8::
- Last address
- 2001:db8:0:fff:ffff:ffff:ffff:ffff
- Typical role
- Multi-tenant building or campus delegation
A /52 in documentation space
Using 2001:db8::/32 (RFC 3849 documentation space) aligned to its own boundary, a /52 occupies:
| Block | First address | Last address |
|---|---|---|
| 2001:db8::/52 | 2001:db8:: | 2001:db8:0:fff:ffff:ffff:ffff:ffff |
How an IPv6 /52 prefix works
A /52 prefix pins the first 52 bits of a 128-bit address, leaving 76 bits free. That free portion holds 276 = 75,557,863,725,914,323,419,136 distinct addresses, and every such block begins at a multiple of that size. Because each subnet should be a /64, the 12 middle bits between the prefix and the /64 boundary give 4,096 subnets to hand out.
Where /52 is used
- Branch offices and individual buildings drawing their own block from a corporate /44 or /48.
- Data-center rows where each rack group needs dozens of /64 segments.
- Business-class ISP delegations sized between residential handouts and full site grants.
Sixteen /56s nest neatly inside a /52, so you can re-delegate home-sized chunks downstream without breaking alignment.
At 4,096 /64s, even aggressive VLAN plans leave thousands of subnets idle — by design.
Frequently asked questions
How many /64s are in a /52?
4,096. Twelve bits separate the prefixes, yielding just over four thousand standard subnets.
How many /56s are in a /52?
Sixteen — four bits' worth, which makes the /52 a natural parent for handing out home-style delegations.
How many addresses does an IPv6 /52 have?
75,557,863,725,914,323,419,136, which is 2^76.
Is a /52 a common delegation size?
It shows up mostly as a business-tier or intermediate delegation: consumer lines more often see /56 or /60, while whole sites typically jump straight to a /48.
Open this prefix in the calculator
Open 2001:db8::/52 in the IPv6 calculator