Autonomous system
AS9426 WESTPAC-AS-AP Westpac Bank
Unclassified APNIC
Summary
Westpac Banking Corporation
enterprise legacy
AS9426 (WESTPAC-AS-AP) is held by Westpac Banking Corporation, one of Australia's four major banks. This is a corporate enterprise AS: the bank running its own routed address space for its branches, corporate sites and internet-facing services, not a network sold to anyone else.
What it's used for
The evidence is a large-enterprise pattern, and the neighbour count is what gives it away. The AS originates 55 IPv4 prefixes totalling 20,992 addresses but is observed with only 3 BGP neighbours. A carrier with 55 routes would be peered with dozens or hundreds of networks; a bank multihomed to two or three Australian transit providers for resilience would look exactly like this. The address inventory is dominated by 166.120.0.0/16, a legacy block registered to Westpac Banking Corporation, sliced up into a long tail of /19s, /20s, /22s and /24s — the deaggregation you get when an enterprise pins individual site or service ranges to particular upstreams. Alongside it sit smaller APNIC-region blocks (203.24.0.0/22, 203.24.4.0/22, 203.23.44.0/24) and 110.5.80.0/20 and its more specifics. No IPv6 prefixes appear in the RIS view.
Notable
- The core block
166.120.0.0/16is registered to Westpac Banking Corporation and dates back to the early 1990s, an era when a large corporate could still obtain a /16 directly. - 55 prefixes against only 3 neighbours is a strong enterprise signature: heavy internal deaggregation, almost no external peering.
- The AS carries no IPv6 in the observed routing table.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-18, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 34 prefixes · 17.41K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| AU | Australia | 34 |
Registry
Allocation record
- Registry
- APNIC
- Handle
AS9426- Registry name
- WESTPAC-AS-AP
- Registrant
- SingTel Optus Pty Ltd
- Abuse contact
- abuse@optusnet.com.au
- Registered
- 2008-09-04
- Last changed
- 2021-01-15
- Allocation
- allocated
Declared
PeeringDB profile
- Name
- Westpac Bank
- Scope
- Not Disclosed
- Traffic ratio
- Not Disclosed
- Peering policy
- Open
PeeringDB records are maintained by the network operator and are not independently verified. Treat them as a statement of intent rather than of fact. For the observed and recorded view, see peering, which lists the exchanges Packet Clearing House has a port on file for.
Routing security
RPKI and IRR
- RPKI
- 96% valid · 46 valid, 2 with no ROA
- ROAs
- 24 authorising AS9426
- ASPA
- no ASPA record
- IRR
- 96% registered · 46 of 48 announcements
- Route objects
- 177 naming AS9426
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 442 networks and 1,784 prefixes, as published 2026-10-19. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere