Autonomous system
AS13172 ESO Electroenergien Sistemen Operator EAD
Unclassified RIPE Enterprise
Summary
Electroenergien Sistemen Operator
infrastructure enterprise government
Every address in a block answers to the same name: the last octet is left out entirely.
What it's used for
- The network of Bulgaria's electricity transmission system operator. 1,536 addresses across five IPv4 prefixes, one IPv6 prefix, and 30 observed BGP neighbours.
Notable
- Three sampled addresses in
91.211.232.0/24all returned91-211-232-host.eso.bg, and the same held in two further blocks. - Netnames are
ESO-EADon two blocks andInetServiceson two others. - The blocks named
InetServiceslist only an abuse contact. - Nine of fifteen sampled addresses returned a name; 30 observed BGP neighbours.
Interesting
- The reverse name is built from three octets, so all 256 addresses in the block share one name. Truncating the last octet turns a per-address identifier into a per-block one, and anything that logs or filters by hostname loses the ability to tell one machine from another. Other networks in this range truncate to two octets or reverse the order; this is the furthest the idea goes.
-hostas a suffix adds nothing a reader can use, which is what remains once the varying part is gone.- 30 neighbours for 1,536 addresses is a peering profile, not an access one. A power grid operator needs paths to many counterparties and almost no address space to do it with.
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
Recorded at 3 exchanges in 2 countries, largest first.
| Exchange | Location | Their address |
|---|---|---|
| NetIX | Sofia, Bulgaria | 185.1.227.93 |
| InterLAN-IX | Bucharest, Romania | 86.104.125.231 |
| Bulgarian Internet eXchange | Sofia, Bulgaria | 193.169.198.172 |
Transit providers
11 upstream, 0 downstream and 18 adjacent networks observed; most-used upstreams first.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-11-03, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 5 prefixes · 1.54K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| BG | Bulgaria | 6 |
Registry
Allocation record
- Registry
- RIPE
- Handle
AS13172- Registry name
- ESO
- Registrant
- NOC-ESO
- Abuse contact
- abuse@eso.bg
- Registered
- 2005-02-04
- Last changed
- 2025-10-27
- Allocation
- allocated
Declared
PeeringDB profile
- Name
- ESO
- Also known as
- ESO
- Network type
- Enterprise
- Scope
- Regional
- Traffic ratio
- Balanced
- Peering policy
- Restrictive
- IRR as-set
AS-SET-ESO- Present at
- 2 exchanges
- Website
- https://www.eso.bg
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
- 100% valid · 9 valid, 0 with no ROA
- ROAs
- 9 authorising AS13172
- ASPA
- no ASPA record
- IRR
- 100% registered · 9 of 9 announcements
- Route objects
- 22 naming AS13172
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: 451 networks and 1,853 prefixes, as published 2026-11-04. 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