cogentco.com
Overall grade based on: IPv4: 1 of 1 complete · IPv6: 1 of 1 complete
All 2 endpoints share identical configuration Select an IP for owner, ASN & location
A+ 38.100.128.10 IPv4 WHOIS › A+ 2001:550:1::cc01 IPv6 WHOIS › Grade Breakdown
Protocol Support 95%
Key Exchange 90%
Cipher Strength 100%
Certificate 100%
Certificate has expired. This domain's SSL/TLS certificate is no longer valid and browsers will show security warnings to visitors.
Protocol Configuration
Supported Protocols
TLS 1.3
TLS 1.2
TLS 1.1
TLS 1.0
SSL 3
SSL 2
Negotiated Cipher
TLS_AES_256_GCM_SHA384
Protocol Details
| Connection | |
| ALPN | http/1.1 |
| SNI Required | No |
| Supported Named Groups | x25519 secp256r1 secp384r1 (inferred) |
| Post-Quantum Key Exchange | Unknown |
| HTTP/3 (QUIC) | Unknown |
| Encrypted Client Hello | Unknown |
| Security Features | |
| Forward Secrecy | Yes (ECDHE / DHE) |
| Downgrade Prevention | Yes (legacy TLS disabled) |
| Secure Renegotiation | Unknown |
| Extended Master Secret | Unknown |
| OCSP Stapling | Unknown (measured on TLS 1.2 only) |
| HSTS | No |
| HSTS Preloading | N/A (HSTS not enabled) |
| Security Checks | |
| BEAST attack | Mitigated |
| POODLE (SSLv3) | No (SSL 3 not supported) |
| POODLE (TLS) | No |
| RC4 | No |
| SSL/TLS Compression | No (not supported by .NET TLS stack) |
| Heartbleed | Not tested |
Cipher Suite Analysis
| Cipher Suite | Hex | Key Exchange | FS | Bits | Strength |
|---|---|---|---|---|---|
| # TLS 1.3 | |||||
| TLS_AES_256_GCM_SHA384 | 0x1302 | ECDHE | FS | 256 | Secure |
| TLS_CHACHA20_POLY1305_SHA256 | 0x1303 | ECDHE | FS | 256 | Secure |
| TLS_AES_128_GCM_SHA256 | 0x1301 | ECDHE | FS | 128 | Secure |
| # TLS 1.2 | |||||
| TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | 0xC030 | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 256 | Secure |
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | 0xC02F | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 128 | Secure |
| TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 | 0x009F | DH 2048 bits | FS | 256 | Secure |
| TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 | 0x009E | DH 2048 bits | FS | 128 | Secure |
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA | 0xC014 | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 256 | Weak |
| TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 | 0x006B | DH 2048 bits | FS | 256 | Weak |
| TLS_DHE_RSA_WITH_AES_256_CBC_SHA | 0x0039 | DH 2048 bits | FS | 256 | Weak |
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 | 0xC027 | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 128 | Weak |
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA | 0xC013 | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 128 | Weak |
| TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 | 0x0067 | DH 2048 bits | FS | 128 | Weak |
| TLS_DHE_RSA_WITH_AES_128_CBC_SHA | 0x0033 | DH 2048 bits | FS | 128 | Weak |
| TLS_RSA_WITH_AES_256_GCM_SHA384 | 0x009D | RSA | No FS | 256 | Weak |
| TLS_RSA_WITH_AES_128_GCM_SHA256 | 0x009C | RSA | No FS | 128 | Weak |
| TLS_RSA_WITH_AES_256_CBC_SHA256 | 0x003D | RSA | No FS | 256 | Weak |
| TLS_RSA_WITH_AES_256_CBC_SHA | 0x0035 | RSA | No FS | 256 | Weak |
| TLS_RSA_WITH_AES_128_CBC_SHA256 | 0x003C | RSA | No FS | 128 | Weak |
| TLS_RSA_WITH_AES_128_CBC_SHA | 0x002F | RSA | No FS | 128 | Weak |
| TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 | 0xCCA8 | ECDH secp256r1 (eq. 3072 bits RSA) | FS | 256 | Secure |
Handshake Simulation
| Client | Protocol | Cipher Suite | Result |
|---|---|---|---|
| Chrome 120 / Win 11 | TLS 1.3 | TLS_AES_256_GCM_SHA384 | Success |
| Chrome 80 / Win 10 | TLS 1.3 | TLS_AES_256_GCM_SHA384 | Success |
| Firefox 115 / Win 10 | TLS 1.3 | TLS_AES_256_GCM_SHA384 | Success |
| iOS 17 / Safari | TLS 1.3 | TLS_CHACHA20_POLY1305_SHA256 | Success |
| macOS 14 / Safari | TLS 1.3 | TLS_AES_256_GCM_SHA384 | Success |
| Android 14 | TLS 1.3 | TLS_AES_128_GCM_SHA256 | Success |
| Chrome 69 / Win 7 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Chrome 49 / XP SP3 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | Success |
| IE 11 / Win 10 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| IE 11 / Win 7 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Android 9.0 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Android 7.0 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Android 5.0 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | Success |
| Android 4.4.2 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Java 11 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 | Success |
| Java 8u121 | TLS 1.2 | TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 | Success |
| Android 4.0.4 | - | - | No |
| Android 4.1.1 | - | - | No |
| Baidu Jan 2015 | - | - | No |
| Java 6 | - | - | No |
* Simulated based on server's supported protocols and cipher configuration.
Certificate Identity
| Common Name | cogentco.com |
| Alt Names | *.cnms.cogentco.com *.cogentco.com *.dev.cogentco.com *.dns.cogentco.com *.elk.cogentco.com *.globalpeerconnect.com *.globalpeerexchange.com *.lb.cogentco.com *.ms.cogentco.com *.prod.cogentco.com *.rmq.cogentco.com *.stg.cogentco.com *.sys.cogentco.com cogentco.com globalpeerconnect.com globalpeerexchange.com |
| Issuer | CN=YR1, O=Let's Encrypt, C=US |
| Validity | 2026-06-10 to 2026-09-08 (61 days ago — expired) |
| Key | RSA 2048 bits (sha256RSA) |
| Serial Number | 06C432ACD66E0CC84823558243A6C36BA20B |
| SHA256 Fingerprint | 6624820178d021c6c768618659ff7821f4f4c8ac154c8e4beffa1a9b9232cad6 |
| Pin SHA256 | /ljtAvOb9heTO5sZ2zKcYYFmfmAVOqQ3Jr78NjAPP6c= |
Certificate Properties
| Type | DV |
| Cert Transparency | Yes (SCT) |
| OCSP Must Staple | No |
| Revocation | Good (not revoked) OCSP: http://yr1.i.lencr.org/ |
| DNS CAA | No (missing) |
| Trusted By | Yes Mozilla · Apple · Android · Java · Windows |
| Validity Period | 90 days (maximum 200 days for certificates issued then) |
| Chain Issues | • Contains anchor (root CA included in chain) |
Trust Chain Architecture
End-Entity Certificate
CN=cogentco.com (Issuer: CN=YR1, O=Let's Encrypt, C=US)
Intermediate CA
CN=YR1, O=Let's Encrypt, C=US (Issuer: CN=Root YR, O=ISRG, C=US)
Intermediate CA
CN=Root YR, O=ISRG, C=US (Issuer: CN=ISRG Root X1, O=Internet Security Research Group, C=US)
Root Certificate
CN=ISRG Root X1, O=Internet Security Research Group, C=US (Issuer: CN=ISRG Root X1, O=Internet Security Research Group, C=US)
TLS History & Relations
Everything our scans have seen for cogentco.com, first seen 2026-07-24; current certificate since 2026-07-24.
Certificates served
| Certificate (SHA-256) | Issuer | Valid | Served |
|---|---|---|---|
| 6624820178d021c6… current | YR1 | 2026-06-10 → 2026-09-08 | 2026-07-24 |
Addresses
| Address | Certificate | Seen |
|---|---|---|
| 38.100.128.10 | 6624820178d021c6… | 2026-07-24 |
| 2001:550:1::cc01 | 6624820178d021c6… | 2026-07-24 |
TLS history (a row per change; repeated checks only extend it)
| Since → last checked (UTC) | Grade | TLS | Certificates | Addresses |
|---|---|---|---|---|
| 2026-07-24 07:27 | A+ | TLS 1.3 | 6624820178d021c6… | 38.100.128.10, 2001:550:1::cc01 |
Other domains on the same certificate
- globalpeerconnect.com 2 names *.globalpeerconnect.com
- globalpeerexchange.com 2 names *.globalpeerexchange.com