asn.dev

Address space

AS25 UCB - University of California at Berkeley

Unclassified ARIN

IPv4 prefixes 15 200K addresses
IPv6 prefixes 32
Most common size /24 IPv4
Flagged 4

Shape

IPv4 prefix sizes

All IPv4
/16
/16: 2
2
/17
/17: 1
1
/18
/18: 2
2
/22
/22: 1
1
/23
/23: 2
2
/24
/24: 5
5
/31
/31: 2
2

A wall of /24s usually means many small customer assignments or fine-grained traffic engineering; a few short prefixes means large contiguous allocations announced whole.

Shape

IPv6 prefix sizes

All IPv6
/33
/33: 1
1
/35
/35: 2
2
/36
/36: 2
2
/37
/37: 2
2
/38
/38: 2
2
/39
/39: 2
2
/40
/40: 2
2
/41
/41: 2
2
/42
/42: 2
2
/43
/43: 2
2
/44
/44: 2
2
/45
/45: 2
2
/46
/46: 2
2
/47
/47: 2
2
/48
/48: 3
3
/123
/123: 2
2

Geography

Where the space lands

CountryNamePrefixes
USUnited States of America47

Review

Flagged prefixes

4 of 47
PrefixFamilyAddressesCountryFlags
137.164.3.26/31IPv42USToo specific
137.164.50.20/31IPv42USToo specific
2607:f380::118:9a40:31a0/123IPv6/123USToo specific
2607:f380:1::118:9a43:2140/123IPv6/123USToo specific

A flag is an observation, not an accusation. Very large and very specific prefixes are both legitimate in the right context.