AS18438 — BROWNB - Brown Brothers Harriman & Company

AS18438 announces 9 IPv4 prefixes covering 5,120 addresses and 0 IPv6 prefixes.

About this network

BROWNB is the autonomous system for Brown Brothers Harriman & Company.

What it's used for

• The address space carries corporate infrastructure, evidenced by netnames BBHNET, BBHNET1, and BBHNET8 registered to Brown Brothers Harriman & Company.
• The AS announces 5120 IPv4 addresses across 9 prefixes with 9 observed neighbours, indicating a small, self-contained corporate network rather than a transit or access provider.

Notable

• Registrants align with the announcer for most prefixes, listing Brown Brothers Harriman & Company or Brown Brothers Harriman & Co., though two prefixes (192.200.4.0/22 and 192.200.2.0/23) are registered to "Various Registries (Maintained by ARIN)" with netname NET192.
• The inventory consists of a mix of /21, /22, /23, and /24 blocks, primarily in the 204.136.0.0/16 and 192.200.0.0/16 ranges, with no IPv6 prefixes announced.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 192.200.1.0/24
• 192.200.2.0/23
• 192.200.4.0/22
• 192.200.8.0/24
• 204.136.16.0/24
• 204.136.19.0/24
• 204.136.20.0/24
• 204.136.23.0/24
• 204.136.24.0/21

Upstream networks

• AS55002 F5, Inc.
• AS174 Cogent Communications, LLC
• AS12271 Charter Communications Inc
• AS3356 Level 3 Parent, LLC
• AS54004 Cablevision Lightpath LLC
• AS2516 KDDI CORPORATION
• AS8220 COLT Technology Services Group Limited
• AS6461 Zayo Bandwidth
• AS9141 P4 Sp. z o.o.

Adjacent networks

• AS55002 F5, Inc.
• AS174 Cogent Communications, LLC
• AS12271 Charter Communications Inc
• AS3356 Level 3 Parent, LLC
• AS54004 Cablevision Lightpath LLC
• AS2516 KDDI CORPORATION
• AS8220 COLT Technology Services Group Limited
• AS6461 Zayo Bandwidth
• AS9141 P4 Sp. z o.o.

Routing security

• RPKI: 3 valid, 0 invalid and 17 not-found announcements; 3 ROAs.
• ASPA: none published.
• IRR: 95% of announcements registered; 37 route objects.
• Listed in as-sets: AS-BROWNB, AS-CCF, AS-CCF-TEST, AS-DEFENSE, AS-F5, AS-HURRICANE, AS-KDD, AS-PNAPBSN, AS-PNAPNYM, AS-RR-BIZ, AS-SUNGARDASNA, AS-XO-B, AS1221:AS-CUSTOMERS, AS35280:AS-DEFENSE, AS35280:AS-F5, AS54004:AS-CUSTOMERS, AS6128:AS-CUSTOMERS, AS8220:AS-COLTUK, AS9141:AS-P4NET.