Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

98 hosts · 367 ms

HostCertsFirst seenLast seenDNS
acerta.be 31 2026-01-13 2026-09-15 ok
*.acerta.be 5 2025-09-15 2026-08-31 —
tdrsbc01.acerta.be 2 2025-09-04 2026-09-10 ok
www.tdrsbc01.acerta.be 1 2025-09-04 2025-09-04 nxdomain
dimona.acerta.be 5 2026-05-12 2026-09-24 ok
a-dimona.acerta.be 6 2026-05-14 2026-09-26 ok
t-dimona.acerta.be 6 2026-05-17 2026-09-30 ok
oa.acerta.be 1 2026-03-26 2026-03-26 ok
data.acerta.be 3 2026-03-26 2026-10-01 ok
owa.acerta.be 1 2026-03-26 2026-03-26 ok
hybrid.acerta.be 1 2026-03-26 2026-03-26 ok
connecthroffice.acerta.be 5 2026-05-25 2026-09-22 ok
a-connecthroffice.acerta.be 5 2026-04-28 2026-08-26 ok
t-connecthroffice.acerta.be 5 2026-04-29 2026-08-27 ok
maintenance.acerta.be 8 2026-05-16 2026-09-30 ok
juricible.acerta.be 7 2026-03-03 2026-09-08 ok
research.acerta.be 3 2026-04-29 2026-09-29 ok
*.research.acerta.be 3 2026-04-29 2026-09-29 —
api.acerta.be 3 2026-02-06 2026-02-24 ok
a-api.acerta.be 6 2026-02-06 2026-09-07 ok
d-api.acerta.be 3 2026-02-06 2026-02-24 ok
t-api.acerta.be 3 2026-02-06 2026-02-24 ok
afspraak.acerta.be 8 2026-05-16 2026-09-29 ok
kbc-devportal.acerta.be 2 2026-02-23 2026-02-24 nxdomain
a-kbc-devportal.acerta.be 3 2026-02-23 2026-02-24 nxdomain
mail.acerta.be 1 2026-03-26 2026-03-26 ok
email.acerta.be 7 2026-03-11 2026-09-08 ok
*.email.acerta.be 2 2025-08-23 2026-07-24 —
www.email.acerta.be 6 2026-05-19 2026-10-01 ok
rum.acerta.be 5 2026-01-12 2026-09-07 ok
a-rum.acerta.be 6 2026-01-12 2026-09-07 ok
d-rum.acerta.be 5 2026-01-12 2026-09-07 ok
t-rum.acerta.be 5 2026-01-12 2026-09-07 ok
afspraken.acerta.be 4 2026-04-16 2026-09-15 ok
starten.acerta.be 8 2026-05-16 2026-09-29 ok
campaign.acerta.be 1 2025-08-08 2025-08-08 nxdomain
signin.acerta.be 6 2025-10-31 2026-10-01 ok
a-signin.acerta.be 6 2025-10-31 2026-09-07 ok
d-signin.acerta.be 8 2025-10-31 2026-10-04 ok
t-signin.acerta.be 7 2025-10-31 2026-09-30 ok
*.notification.acerta.be 1 2025-11-10 2025-11-10 —
vika-demo.acerta.be 1 2025-08-08 2025-08-08 nxdomain
sso.acerta.be 7 2025-08-08 2026-09-29 ok
a-sso.acerta.be 7 2025-10-09 2026-09-28 ok
t-sso.acerta.be 6 2026-05-21 2026-10-02 ok
trefzeker.acerta.be 7 2026-03-03 2026-09-08 ok
netto-planner.acerta.be 2 2025-07-30 2026-06-28 ok
nettoplanner.acerta.be 10 2025-07-30 2026-09-30 ok
netplanner.acerta.be 2 2025-07-30 2026-06-28 ok
autodiscover.acerta.be 1 2026-03-26 2026-03-26 ok
dc1-a-frontdoor.acerta.be 1 2025-08-01 2025-08-01 nxdomain
dc2-a-frontdoor.acerta.be 1 2025-08-01 2025-08-01 ok
dc3-a-frontdoor.acerta.be 1 2025-08-01 2025-08-01 ok
dc1-p-frontdoor.acerta.be 1 2025-08-04 2025-08-04 ok
dc2-p-frontdoor.acerta.be 1 2025-08-04 2025-08-04 nxdomain
dc3-p-frontdoor.acerta.be 1 2025-08-04 2025-08-04 ok
dc1-t-frontdoor.acerta.be 1 2025-07-17 2025-07-17 nxdomain
dc2-t-frontdoor.acerta.be 1 2025-07-17 2025-07-17 ok
dc3-t-frontdoor.acerta.be 1 2025-07-17 2025-07-17 ok
jobs.acerta.be 10 2026-04-28 2026-08-24 ok
tools.acerta.be 4 2026-04-20 2026-08-22 ok
labelcms.acerta.be 6 2026-05-08 2026-09-20 ok
staging.labelcms.acerta.be 6 2026-05-14 2026-09-26 ok
dev.labelcms.acerta.be 6 2026-05-21 2026-10-03 ok
*.operations.acerta.be 2 2025-07-23 2026-06-23 —
mailers.acerta.be 1 2026-03-26 2026-03-26 ok
clientaccess.acerta.be 6 2025-08-08 2026-09-07 ok
a-clientaccess.acerta.be 8 2025-10-09 2026-09-07 ok
t-clientaccess.acerta.be 6 2026-05-14 2026-09-26 ok
helm-multiess.acerta.be 5 2026-05-01 2026-08-29 ok
groups-multiess.acerta.be 5 2026-04-28 2026-08-26 ok
evenements.acerta.be 7 2026-03-03 2026-09-08 ok
payments.acerta.be 1 2025-08-08 2025-08-08 nxdomain
events.acerta.be 8 2026-05-16 2026-09-29 ok
rendezvous.acerta.be 7 2026-05-16 2026-09-29 ok
chat.acerta.be 8 2026-05-16 2026-10-01 ok
webconnect.acerta.be 1 2025-11-07 2025-11-07 ok
docs-central.acerta-ict.acerta.be 4 2026-04-11 2026-08-10 ok
simulationnet.acerta.be 2 2025-07-30 2026-06-28 ok
mft.acerta.be 1 2026-02-23 2026-02-23 ok
a-mft.acerta.be 1 2026-02-16 2026-02-16 ok
t-mft.acerta.be 1 2026-02-16 2026-02-16 ok
consult.acerta.be 7 2026-03-11 2026-09-08 ok
www.consult.acerta.be 6 2026-05-16 2026-10-01 ok
t-api-dev.acerta.be 3 2026-02-06 2026-02-24 ok
servicenow.acerta.be 4 2026-04-21 2026-08-19 ok
a-servicenow.acerta.be 5 2026-05-16 2026-09-13 ok
d-servicenow.acerta.be 4 2026-04-10 2026-08-08 ok
www.acerta.be 5 2026-01-18 2026-09-07 ok
simtax.acerta.be 2 2026-03-01 2026-07-17 ok
a-simtax.acerta.be 2 2026-03-02 2026-07-20 nxdomain
*.a-simtax.acerta.be 2 2026-03-02 2026-07-20 —
t-simtax.acerta.be 1 2026-05-04 2026-05-04 nxdomain
*.t-simtax.acerta.be 1 2026-05-04 2026-05-04 —
*.simtax.acerta.be 2 2026-03-01 2026-07-17 —
api-az.acerta.be 6 2026-05-14 2026-09-27 ok
a-api-az.acerta.be 1 2026-06-02 2026-06-02 ok
t-api-az.acerta.be 6 2026-05-14 2026-09-27 ok

Programmatic access, with DNS A records: API GET /v1/hosts/acerta.be (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/acerta.be.