~/dnsniffer/issuers/cisco-systems·rank #71
$ dnsniffer count --issuer cisco-systems --active
▸ How many domains does Cisco Systems secure?
2,274
active domains whose current TLS certificate was issued by Cisco Systems, as of - 0.00% of all attributed domains.
# rank #71 of all CAs# all records held: 2,292# subdomains: 6,350# intermediates: 2# United States
~/issuers/cisco-systems/history·active domains
2,274
domains secured by Cisco Systems on 2026-09-01 · ▲ +347 (+18.01%) since 2025-06-30
# y-axis starts at 2K, not zero - domain counts move by fractions of a percent a day. Dashed segments are estimated: reconstructed from certificate first-seen dates before daily snapshots began, not measured on the day.
# change over time
30 days
▲ +0.18%
+4 domains
90 days
▲ +0.71%
+16 domains
1 year
▲ +7.67%
+162 domains
# intermediate CAs
| intermediate | country | domains |
|---|---|---|
| HydrantID Server CA O1 | United States | 2,274 |
| Cisco Meraki CA | United States | 0 |
# faq
- ? How many domains does Cisco Systems secure?
- Cisco Systems is the certificate authority for 2,274 active domains as of September 1, 2026 - 0.00% of every domain DNSniffer can attribute to an issuer.
- ? Is Cisco Systems gaining or losing market share?
- The number of domains secured by Cisco Systems has grown by 7.67% over the last year (+162 domains).
- ? Which intermediate CAs does Cisco Systems sign from?
- We have seen 2 intermediates under Cisco Systems, the busiest being “HydrantID Server CA O1” with 2,274 domains. The full list, with per-intermediate counts, is on this page.
- ? Where does this number come from?
- DNSniffer ingests Certificate Transparency logs continuously and records the issuer of the most recent certificate seen for each domain, then snapshots the per-issuer count once a day. It measures how much of the live web a CA currently secures, not how many certificates it has issued over its lifetime.