DNS
THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.3

cogentco.com · 38.100.128.10:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
CN=cogentco.com
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-10-10T04:58:35+00:00
Expires
2027-01-08T04:58:34+00:00
Days remaining
62
Serial (hex)
05E3B804CBC0E61F75B42EFA3EFDBD273257
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.cnms.cogentco.com, DNS:*.cogentco.com, DNS:*.dev.cogentco.com, DNS:*.dns.cogentco.com, DNS:*.elk.cogentco.com, DNS:*.globalpeerconnect.com, DNS:*.globalpeerexchange.com, DNS:*.lb.cogentco.com, DNS:*.ms.cogentco.com, DNS:*.prod.cogentco.com, DNS:*.rmq.cogentco.com, DNS:*.stg.cogentco.com, DNS:*.sys.cogentco.com, DNS:cogentco.com, DNS:globalpeerconnect.com, DNS:globalpeerexchange.com

SHA-256 fingerprint

9E:18:A2:1E:AB:2B:17:2F:5F:19:E6:61:A5:0A:72:34:EE:9F:78:1C:50:BA:3F:E9:22:F7:C9:81:F8:A5:75:CC
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
AA:4C:05:D5:A5:1D:F8:48:60:5C:E9:66:6C:0E:79:FA:CB:56:CA:85
authorityKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityInfoAccess
CA Issuers - URI:http://yr1.i.lencr.org/
subjectAltName
DNS:*.cnms.cogentco.com, DNS:*.cogentco.com, DNS:*.dev.cogentco.com, DNS:*.dns.cogentco.com, DNS:*.elk.cogentco.com, DNS:*.globalpeerconnect.com, DNS:*.globalpeerexchange.com, DNS:*.lb.cogentco.com, DNS:*.ms.cogentco.com, DNS:*.prod.cogentco.com, DNS:*.rmq.cogentco.com, DNS:*.stg.cogentco.com, DNS:*.sys.cogentco.com, DNS:cogentco.com, DNS:globalpeerconnect.com, DNS:globalpeerexchange.com
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/88.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F: AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26 Timestamp : Oct 10 05:57:05.575 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:72:BE:9F:DC:94:55:D4:2C:DA:0F:DA:CC: 92:26:BF:0F:0C:8F:82:94:0C:34:DE:59:78:80:9A:E2: 81:9B:A8:C6:02:21:00:DD:95:2C:CA:AE:C2:1C:9C:8C: D5:39:E4:22:A1:73:C1:4E:71:6A:09:73:76:35:B9:93: 97:10:18:00:41:51:DC Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 44:E8:22:FC:2B:AB:0E:92:EE:D0:E9:FA:D6:96:64:60: 27:76:D0:17:60:E0:89:05:09:C9:23:A1:B0:3F:C3:7F Timestamp : Oct 10 05:57:02.714 2026 GMT Extensions: 00:00:05:00:08:A5:8E:95 Signature : ecdsa-with-SHA256 30:45:02:21:00:B6:6F:20:1F:0C:C0:00:89:57:3E:73: 74:72:6A:AE:4E:5B:2F:6E:24:05:51:D4:BD:90:CD:20: B0:2F:6C:44:0D:02:20:44:BE:01:8E:B5:FF:41:2F:B4: D9:27:88:B6:42:18:64:6E:48:CB:95:CA:0F:02:2E:BD: E9:57:A7:8A:0C:9D:33
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-06T17:51:56+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR1
Issuer
C=US O=ISRG CN=Root YR
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
666
Serial (hex)
A20253F15F2691C05DC1CE13B9BCCA4E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

13:94:96:34:D9:9C:D6:FD:6A:A8:0B:C0:34:FE:FA:CC:EB:19:69:FE:EF:98:65:86:71:3E:CD:BB:05:75:8D:3F
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityInfoAccess
CA Issuers - URI:http://yr.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YR
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2127
Serial (hex)
F24B6D17F9D9AD7CB1C9FEA78782699F
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

07:26:39:D0:B1:40:D5:BF:FA:E1:6A:D9:C3:F6:CC:60:86:04:06:21:F5:1E:E6:1A:6D:46:A8:91:5C:07:CF:76
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
authorityInfoAccess
CA Issuers - URI:http://x1.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x1.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

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