Data as of Nov 7, 2026
198.51.42.0/23
No anonymizer space · no proxy exits in 30 daysHeadquarters, USAISC · reallocated from United States Department of Defense (DoD)
Announcement
this exact prefix
No RPKI
Announced by
Type
Business
Recent change
New origin Jun 2026
from AS367 United States Department of Defense (DoD)
Announcements
More specific
Announcements inside
| Prefix | Origin | Type | Holder | RPKI |
|---|---|---|---|---|
| 198.51.42.0/24 since Jun 2026 | AS1540 | Business | United States Department of Defense (DoD) via Headquarters, USAISC | |
| 198.51.43.0/24 since Jun 2026 | AS1540 | Business | United States Department of Defense (DoD) via Headquarters, USAISC |
Registrations in this block
The registry's network records over the announcement: those covering it, widest first, then every record inside it, under its parent.
| Range | Addresses | Netname | Holder | Type | Created | Abuse contact |
|---|---|---|---|---|---|---|
| 198.51.42.0/23 | 512 | HAMILTON-NET4 | United States Department of Defense (DoD) (USDDD) · US | Direct Allocation | Jan 26, 1993 | disa. |
| └ 198.51.42.0/23 | 512 | HAMILTON-NET4 | Headquarters, USAISC (HEADQU-3) · US | Reallocated | Aug 25, 2025 | — |
| └ 198.51.43.0/24 | 256 | AFRTS-BC-2 | Armed Forces Radio and Television - Broadcast Center (C11328863) · US | Reassigned | Aug 25, 2025 | — |
Network & registry
Registry
Holder
- Organization
- United States Department of Defense (DoD)
- Handle
- USDDD
- Range
- 198.
51. 42. 0/ 23 - Registration type
- Direct Allocation
- Record created
- Jan 26, 1993
- Legacy
- yes
- Reallocated to
- Headquarters, USAISC (HEADQU-3)
- Reallocated
- Aug 25, 2025
Origin network
AS1540
US
- Name
- Headquarters, USAISC
- Type
- Business
- Registered
- May 12, 2004
- Domain
- mail.mil
- Industry
- Internet Service Provider (ISP)
- Spamhaus ASN-DROP
- not listed
Routing timeline
Who has announced this prefix
Summary
Routing history
- Pattern
- Rotating
- First seen
- Feb 2008
- Current origin since
- Jun 2026 · 4 mo
- Origin networks
- 4
- Last change of origin
- Jun 2026
Recorded history
History
- Handoffs
- 3
Whois
Registration for this announcement
- Range
- 198.
51. 42. 0/ 23 - Netname
- HAMILTON-NET4
- Registrant
- Headquarters, USAISC
- Organization
- Headquarters, USAISC (HEADQU-3)
- Org address
- NETC-ANC CONUS TNOSC, Fort Huachuca, AZ, 85613
- Org country
- US
- Type
- Reallocated
- Handle
- NET-198-51-42-0-2
- Parent
- NET-198-51-42-0-1
- Created
- Aug 25, 2025
- RIR
- ARIN
- Country
- US
- Delegated
- Jan 26, 1993
- Status
- assigned
Report abuse
Abuse contact
- nobody@
example. com - Name
- No, Contact Known
- Phone
- +1-800-555-1234
- Handle
- CKN23-ARIN