Every change the tracker has found, newest first. It covers ARIN from 2008-12-01, the RIPE NCC from 2010-04-23, APNIC from 2008-02-15, LACNIC from 2012-06-29 and AFRINIC from 2012-10-03.
2025-11-18ARIN+ AddRestored to the same holderStrong inference
ARIN-Issued
Add 198.135.168.0-198.135.168.255
Inventory
No effect on ARIN applicant inventory
No transfer record matches. ARIN's statistics show it reserved on 2025-11-17 and allocated (dated 2025-11-18) on 2025-11-19. The tracker saw it removed from registration on 2021-07-05 (1597 days earlier), and it is back with the same holder record it had before, so it went back to its previous holder rather than to a new one: most likely a suspension lifted, a reinstatement or a correction.
Evidence (3) · classifier 1.4.0,
ARIN-IssuedARIN-Issued report for 2025-11-18: "Add 198.135.168.0-198.135.168.255"source · retrieved
BeforeARIN delegated statistics 2025-11-17 (produced 2025-11-17T14:00:47+00:00), before the report: reservedsource · retrieved
AfterARIN delegated statistics 2025-11-19 (produced 2025-11-19T14:00:47+00:00), after the report: allocated (dated 2025-11-18)source · retrieved
Classification history for this change (4 versions)
: Restored to the same holder, strong inference (classifier 1.3.0)
: Restored to the same holder, strong inference (classifier 1.3.1)
: Restored to the same holder, strong inference (classifier 1.3.2)
: Restored to the same holder, strong inference (classifier 1.4.0) current
2025-11-18ARIN− RemoveChange to ARIN's own pool recordStrong inference
ARIN-Issued
Remove 198.135.168.0-198.135.168.255
Inventory
Part of the issuance reported the same day
ARIN's statistics show it reserved on 2025-11-17 and allocated (dated 2025-11-18) on 2025-11-19. ARIN removed its own pool record for this range as part of issuing it: the same report adds 198.135.168.0-198.135.168.255. The issuance is explained on that line.
Evidence (3) · classifier 1.4.0,
ARIN-IssuedARIN-Issued report for 2025-11-18: "Remove 198.135.168.0-198.135.168.255"source · retrieved
BeforeARIN delegated statistics 2025-11-17 (produced 2025-11-17T14:00:47+00:00), before the report: reservedsource · retrieved
AfterARIN delegated statistics 2025-11-19 (produced 2025-11-19T14:00:47+00:00), after the report: allocated (dated 2025-11-18)source · retrieved
Classification history for this change (4 versions)
: Change to ARIN's own pool record, strong inference (classifier 1.3.0)
: Change to ARIN's own pool record, strong inference (classifier 1.3.1)
: Change to ARIN's own pool record, strong inference (classifier 1.3.2)
: Change to ARIN's own pool record, strong inference (classifier 1.4.0) current
2021-07-05ARINNot in ARIN-IssuedRemoved (return, revocation or reclamation not publicly distinguishable)Strong inference
Inventory
Possible future reissue candidate after hold
Hold estimate
Estimated hold end 2021-09-03. Possible reissue candidate after this date; not confirmed available.
Removed from active registration. ARIN-Issued didn't list this; the tracker found it by comparing ARIN's daily statistics. ARIN's statistics show it allocated (dated 2020-02-28) on 2021-07-04 and reserved on 2021-07-06. Public sources do not distinguish a voluntary return, revocation, or reclamation. ARIN holds returned, revoked and reclaimed IPv4 space for 60 days before reissuing it, so the estimated hold end is 2021-09-03. This does not confirm availability.
Evidence (3) · classifier 1.4.0,
StatisticsNot listed in ARIN-Issued; found by comparing ARIN's daily statistics: 198.135.168.0/24 allocated on 2021-07-05, reserved on 2021-07-06source · retrieved
BeforeARIN delegated statistics 2021-07-04 (produced 2021-07-04T14:00:13+00:00), before the report: allocated (dated 2020-02-28)source · retrieved
AfterARIN delegated statistics 2021-07-06 (produced 2021-07-06T14:00:14+00:00), after the report: reservedsource · retrieved
Classification history for this change (4 versions)
: Removed (return, revocation or reclamation not publicly distinguishable), strong inference (classifier 1.3.0)
: Removed (return, revocation or reclamation not publicly distinguishable), strong inference (classifier 1.3.1)
: Removed (return, revocation or reclamation not publicly distinguishable), strong inference (classifier 1.3.2)
: Removed (return, revocation or reclamation not publicly distinguishable), strong inference (classifier 1.4.0) current
ARIN's transfer log records a transfer from AECOM (ARIN) to USMatrix (ARIN) on 2020-02-28 18:49 UTC. ARIN-Issued lists it as "Add" because the registration changed hands; it is not a new allocation from ARIN.
Evidence (4) · classifier 1.4.0,
ARIN-IssuedARIN-Issued report for 2020-02-28: "Add 198.135.168.0-198.135.168.255"source · retrieved
Transfer logTransfer log: RESOURCE_TRANSFER on 2020-02-28 18:49 UTC, AECOM (ARIN) to USMatrix (ARIN); resources moved: 198.135.168.0/24source · retrieved
BeforeARIN delegated statistics 2020-02-27 (produced 2020-02-27T15:00:13+00:00), before the report: assigned (dated 1993-05-18)source · retrieved
AfterARIN delegated statistics 2020-02-29 (produced 2020-02-29T15:00:13+00:00), after the report: allocated (dated 2020-02-28)source · retrieved
Classification history for this change (4 versions)
: Intra-ARIN transfer, confirmed (classifier 1.4.0) current
2019-10-16ARINTransfer logMerger/acquisition or reorganizationConfirmed
Transfer log
Merger/acquisition: Rust Environment & Infrastructure (ARIN) to AECOM (ARIN)
From
Rust Environment & Infrastructure ARIN
To
AECOM ARIN
Inventory
No effect on ARIN applicant inventory
ARIN's transfer log records a merger, acquisition or reorganization from Rust Environment & Infrastructure (ARIN) to AECOM (ARIN) on 2019-10-16 20:48 UTC. The registration changed hands; it is not a new allocation from ARIN. ARIN-Issued and ARIN's statistics don't show this change; only the transfer log records it.
Evidence (3) · classifier 1.4.0,
Transfer logTransfer log: MERGER_ACQUISITION on 2019-10-16 20:48 UTC, Rust Environment & Infrastructure (ARIN) to AECOM (ARIN); resources moved: 198.135.168.0/24source · retrieved
BeforeARIN delegated statistics 2019-10-15 (produced 2019-10-15T14:00:13+00:00), before the report: assigned (dated 1993-05-18)source · retrieved
AfterARIN delegated statistics 2019-10-17 (produced 2019-10-17T14:00:13+00:00), after the report: assigned (dated 1993-05-18)source · retrieved
Transfer records (2)
Date (UTC)
Log
Type
Range moved
From
To
ARIN
Resource transfer
198.135.168.0/24
AECOM ARIN
USMatrix ARIN
ARIN
Merger acquisition
198.135.168.0/24
Rust Environment & Infrastructure ARIN
AECOM ARIN
Every record in the ARIN, RIPE NCC, APNIC, LACNIC and AFRINIC transfer logs that moved any part of this IPv4 range (ARIN's from 2009, the RIPE NCC's from 2012, APNIC's from 2010, LACNIC's from 2016, AFRINIC's from 2018). A transfer between two registries is in both logs.
RDAP lookups
Not looked up. The tracker queries RDAP for changes as they're reported (on first sight, after 24 hours and after seven days); older changes aren't looked up because today's RDAP says nothing about the past.