AS43757 — ICZAS-CZ ICZ a.s.

AS43757 announces 2 IPv4 prefixes covering 2,304 addresses and 1 IPv6 prefixes.

About this network

The AS handle ICZAS- is held by ICZ a.s.

What it's used for

• The address space carries corporate infrastructure, evidenced by the netnames ICZ-CZ and ICZ-SK and the reverse DNS record fort.i.cz.
• The network announces 2304 IPv4 addresses across 2 prefixes and 1 IPv6 prefix, with 3 observed neighbours, indicating a small-scale business or internal corporate estate rather than a large access or transit provider.
• Traffic from this AS consists of internal corporate endpoints and services for ICZ a.s., a Czech company.

Notable

• Registrants for both announced prefixes are listed as ICZ Hostmaster; ICZ a.s.; Abuse-C Role, which aligns with the AS holder.
• The inventory includes prefixes in both Czechia and Slovakia (indicated by the ICZ-SK netname), suggesting a cross-border corporate presence.
• The address inventory is compact, consisting of a /21 and a /24 in IPv4 and a single /48 in IPv6.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 78.31.24.0/21
• 192.108.126.0/24
• 2001:67c:1578::/48

Upstream networks

• AS6855 Slovak Telekom, a.s.
• AS5610 O2 Czech Republic, a.s.
• AS5578 SWAN, a.s.

Adjacent networks

• AS6855 Slovak Telekom, a.s.
• AS5610 O2 Czech Republic, a.s.
• AS5578 SWAN, a.s.

Routing security

• RPKI: 3 valid, 0 invalid and 0 not-found announcements; 3 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 3 route objects.
• Listed in as-sets: AS-CTIOL, AS-GTSCZ-CUST, AS-SLOVANET.