Regional Carrier & ISP Disruption Matrix
Real-time routing diagnostics, synthetic DNS latency benchmarks, and live outage monitoring across 23 major broadband, cable, and fiber networks.
AT&T Internet & Fiber
AS7018 · United States
Bharti Airtel
AS9498 · India
CenturyLink (Lumen)
AS209 · United States
Cox Communications
AS22773 · United States
EarthLink
AS7065 · United States
Frontier Communications
AS5650 · United States
Google Fiber
AS16591 · United States
Mediacom
AS30036 · United States
NBN (National Broadband Network)
AS4826 · Australia
Optimum (Altice)
AS6128 · United States
Quantum Fiber
AS209 · United States
Reliance Jio
AS55836 · India
Spectrum (Charter)
AS20115 · United States
Starlink (SpaceX)
AS14593 · Global LEO Satellite
Suddenlink (Optimum West)
AS6128 · United States
T-Mobile 5G Home Internet
AS21928 · United States
Verizon Broadband & 5G Home
AS701 · United States
Verizon Fios
AS701 · United States
Vi (Vodafone Idea)
AS132164 · India
Vodafone Broadband
AS1273 · United Kingdom
Windstream (Kinetic)
AS7029 · United States
Xfinity (Comcast)
AS7922 · United States
Ziply Fiber
AS27017 · United States🌐 Public High-Speed DNS Benchmark vs Default ISP Resolvers
When an ISP experiences localized DNS cache exhaustion, internet traffic fails to resolve domain names. Bypassing your carrier default DNS with any of the verified public resolvers below restores immediate connectivity:
| Resolver Provider | Primary IPv4 | Secondary IPv4 | Global Mean Latency | Security & Privacy |
|---|---|---|---|---|
| Cloudflare DNS | 1.1.1.1 | 1.0.0.1 | 8.2 ms | Zero logs, DNSSEC, DoH/DoT |
| Google Public DNS | 8.8.8.8 | 8.8.4.4 | 11.4 ms | Global Anycast, GeoIP routing |
| Quad9 DNS | 9.9.9.9 | 149.112.112.112 | 13.8 ms | Built-in malware/phishing protection |
| Cisco OpenDNS | 208.67.222.222 | 208.67.220.220 | 14.5 ms | Phishing protection, customizable |
❓ Frequently Asked Questions
How can I tell if my internet outage is my router or my ISP?
Check your modem front indicator lights. If the "Online" or "WAN" LED is solid green/white, your connection to the ISP is active and the issue is likely your local Wi-Fi router or device DNS cache. If the "US/DS" or "Optical/LOS" LED is flashing amber or solid red, your modem cannot synchronize with the ISP optical headend, indicating a verified provider-side outage.
Can changing DNS servers fix an ISP broadband outage?
Yes, if the outage is caused by provider DNS resolver congestion or DDoS attacks. Setting public resolvers like Cloudflare (1.1.1.1) or Google Public DNS (8.8.8.8) on your router allows your devices to resolve domain names even when your ISP default DNS is down.
How often are carrier routing diagnostics updated on IsDownNow?
IsDownNow aggregates network health metrics every 3 to 4 minutes across distributed monitoring nodes, combining BGP routing latency probes, past 1-hour breakout search queries, and authoritative status feeds.