AS20404 NRG Energy, Inc.

AS20404 - NRG Energy, Inc. · registered in the United States

IPv4 addresses2,3046 prefixes · <0.001% of announced IPv4

Rank in United States#5,895largest network in US by IPv4 space, of 18,338 · <0.01% of US

Rank worldwide#20,887of 79,396 networks with IPv4

IPv6noneno IPv6 routes announced

CountryUnited States18,679 ASNs registered there

Open AS20404 in ASN lookup Look up an IP in this network (158.81.153.1) All networks in United States

IPv4 prefixes

All 6 prefixes, in address order.

158.81.153.0/24
158.81.160.0/24
158.81.168.0/24
158.81.208.0/22
158.81.251.0/24
158.81.252.0/24

Other ASNs named NRG Energy, Inc.

1 other network uses the same organisation name; together with AS20404 they announce 6,912 IPv4 addresses.

ASNNameIPv4 addresses

AS55102NRG-NS-2 - NRG Energy, Inc. US4,608

Similar-sized networks in United States

ASNNameIPv4 addresses

AS20100#5892 INFRADAPT - Infradapt2,304

AS20260#5893 SAWTEL-UC - Sawtel, Inc2,304

AS20314#5894 ISP-ROUTER - Conagra Brands Inc.2,304

AS20460#5896 MYTHOSTECH - TFB NET2,304

AS21787#5897 CERIDIAN - CERIDIAN2,304

AS21874#5898 MMC - MMC2,304

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources