Charter (Spectrum) IP Ranges
Charter Communications sells residential and business internet under the Spectrum brand, registered with ARIN as AS20115 under the AS name CHARTER-20115 since March 2001. Its reverse DNS marks which of those two products an address belongs to.
- Provider
- Charter (Spectrum)
- Primary ASN
- AS20115
- Category
- ISP
- Headquarters
- Stamford, CT, USA
- Announced IPv4 prefixes
- 2411
- Registry
- ARIN
Known IP ranges
These prefixes are currently announced to the global routing table by AS20115 (CHARTER-20115 - Charter Communications LLC). Prefix sets change over time - use WHOIS Lookup for the authoritative record on any specific address.
47.132.0.0/15
131.93.0.0/16
23.84.0.0/16
24.217.0.0/16
23.87.0.0/16
47.226.0.0/16
67.150.0.0/16
147.219.0.0/16
47.229.0.0/16
66.52.0.0/16
2603:6090::/28
2603:9010::/30
2600:6c20::/31 (IPv6)
What does a Charter (Spectrum) IP mean in a privacy test?
A Spectrum address as your visible IP means the connection reached the site over your own Charter line with nothing tunnelling it. Whether it is a home or a business line is readable from the address rather than guessed at: Charter names residential and business addresses in different reverse-DNS zones, which is more than most carriers give you.
Where to get Charter's address list
Charter publishes no allowlist. A cable operator has no reason to - a rule that admits Spectrum subscribers admits several tens of millions of homes - so the registry is the source. ARIN holds AS20115 as CHARTER-20115, registered to Charter Communications LLC on 26 March 2001, and the prefixes above are the largest currently announced under it. The AS20115 page carries the registry record alongside the routing data.
Individual blocks repay a direct query, because this network was assembled rather than grown: Charter closed its combination with Time Warner Cable and its acquisition of Bright House Networks on 18 May 2016. ARIN's per-block records keep their own net names and their own dates - 24.217.0.0/24, for instance, is registered as CHTRSTL-BLK-1-MOPL to Charter Communications LLC with an allocation date of 19 April 2000, sixteen years before that closing. A per-address WHOIS query returns those net names, so one ASN hands back many differently labelled records.
Telling a Spectrum home line from a Spectrum business line
This is one of the few consumer networks whose reverse DNS answers the question directly. Charter names addresses as syn- followed by the four octets zero-padded, then a zone: syn-047-132-000-001.res.spectrum.com for 47.132.0.1 and syn-024-217-000-001.biz.spectrum.com for 24.217.0.1. The res label is residential service and the biz label is business service, so a single PTR query separates a household from a shop, an office, or a small server somebody put on a business line.
What the split does not do is turn a business address into a data centre address. Both zones are subscriber access rather than rented compute, so neither is space a stranger can put a proxy on by signing up for an hour of it. Static addressing is something a Spectrum business account buys and residential service does not offer, which makes a Spectrum address that has stayed fixed a reasonable sign of business premises and a changing one a reasonable sign of a home.
Related tools
Frequently asked questions
What IP ranges does Charter (Spectrum) use?
Charter announces its Spectrum address space under AS20115, registered with ARIN to Charter Communications LLC. The largest blocks currently routed there are listed above. Charter publishes no allowlist file, so the ARIN record for AS20115 and the routing table are the checkable sources.
Why does a Charter (Spectrum) IP appear in my privacy test?
A Spectrum address as your visible IP means the connection reached the site over your own Charter line with nothing tunnelling it. Whether it is a home or a business line is readable from the address rather than guessed at: Charter names residential and business addresses in different reverse-DNS zones, which is more than most carriers give you.
Is this Spectrum address a home line or a business line?
The reverse DNS says which. Charter names addresses as syn- plus the zero-padded octets, then res.spectrum.com for residential service or biz.spectrum.com for business service. A PTR query on the address returns one or the other, so no guessing from the block is needed.
Does Spectrum give residential customers a static IP?
No. A static address is a business product at Spectrum; residential service assigns addresses dynamically from Charter's pools, so a home address can change. That is why a Spectrum address that has stayed fixed for a long time more often belongs to a business line than to a household.
Why does a WHOIS lookup on a Spectrum IP return a net name I do not recognise?
Because ARIN records the individual block as well as the ASN, and the block carries its own label. 24.217.0.0/24, for example, is registered as CHTRSTL-BLK-1-MOPL to Charter Communications LLC with an allocation date of 19 April 2000. The ASN stays AS20115 whatever the per-block net name reads.