`cfrent.cz`

DNSSEC	🔒 Signed (DS record present)
A	2001:1568::13^{🇨🇿 WEB4U2001:1568::/33}
		PTR	`php56.web4u.cz`
A	81.91.86.13^{🇨🇿 WEB4U81.91.80.0/21}
NS	`ns2.web4u.cz` ⭐
		A	2a02:a40:100:28ff::12^{🇨🇿 BlueTone-AS2a02:a40::/32 Ceske Radiokomunikace, a.s.}
			PTR	`ns2.web4u.cz`
		A	85.207.53.12^{🇨🇿 BlueTone-AS85.207.0.0/16 BlueTone-CRa-CZ Fourth address block}
			PTR	`ns2.web4u.cz`
NS	`ns.web4u.cz`
		A	2001:1568:fd::241^{🇨🇿 WEB4U2001:1568::/33}
			PTR	`ns.web4u.cz`
		A	185.14.224.241^{🇨🇿 WEB4U185.14.224.0/23}
			PTR	`ns.web4u.cz`
MX	`mx1.mailchannels.net` ⭐
		A	54.187.177.89^{🇺🇸 Amazon54.186.0.0/15 EC2 PDX prefix}
			PTR	`ec2-54-187-177-89.us-west-2.compute.amazonaws.com`
MX	`mx2.mailchannels.net` ⭐
		A	54.187.177.89^{🇺🇸 Amazon54.186.0.0/15 EC2 PDX prefix}
			PTR	`ec2-54-187-177-89.us-west-2.compute.amazonaws.com`
SOA	`ns.web4u.cz`admin@web4u.cz 2025-05-02 #0

`cz`

	DNSSEC	🔒 Signed (DS record present)
	NS	`a.ns.nic.cz` ⭐
	NS	`b.ns.nic.cz`
	NS	`c.ns.nic.cz`
	NS	`d.ns.nic.cz`
	SOA	`a.ns.nic.cz`hostmaster@nic.cz serial=1777441635

Subdomains

mail.cfrent.cz

Same first word

cfrent.com

Similar names

ncrfet.co.za

cnfert.com

cnfert.cn

nfcert.com

fcrent.com

netcrf.de

fncert.com

crfnet.com

cfrnet.com

ctfnre.com.au

fcentr.ru

ntrfce.com

refcnt.org

rfcnet.com

cnfert.cfd

nfcert.org

DNS History

8 records (6 active, 2 former)

●NSns.web4u.cz2015-09-02 → 2026-04-29 · 2 obs

● 2015-09-02 20:03:38
● 2026-04-29 06:09:46

●NSns2.web4u.cz2015-09-02 → 2026-04-29 · 2 obs

● 2015-09-02 20:03:38
● 2026-04-29 06:09:46

○MXmail.cfrent.cz2015-09-02 → 2017-07-27 · 4 obs

● 2015-09-02 20:03:38
● 2017-07-27 04:47:18
○ 2026-04-29 06:09:44
○ 2026-04-29 06:09:46

●MXmx1.mailchannels.net2026-04-29 → 2026-04-29 · 3 obs

○ 2017-07-27 04:47:18
● 2026-04-29 06:09:44
● 2026-04-29 06:09:46

●MXmx2.mailchannels.net2026-04-29 → 2026-04-29 · 3 obs

○ 2017-07-27 04:47:18
● 2026-04-29 06:09:44
● 2026-04-29 06:09:46

●A2001:1568::132016-12-03 → 2026-04-29 · 3 obs

○ 2016-05-27 21:28:08
● 2016-12-03 16:21:28
● 2026-04-29 06:09:46

○A81.91.86.122015-09-02 → 2016-05-27 · 4 obs

● 2015-09-02 20:03:38
● 2016-05-27 21:28:08
○ 2016-12-03 16:21:28
○ 2026-04-29 06:09:46

●A81.91.86.132016-12-03 → 2026-04-29 · 3 obs

○ 2016-05-27 21:28:08
● 2016-12-03 16:21:28
● 2026-04-29 06:09:46

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
cz	c.ns.nic.cz, a.ns.nic.cz, b.ns.nic.cz, d.ns.nic.cz	-
cfrent.cz	ns.web4u.cz, ns2.web4u.cz	4 records

✅ Authoritative Response

Server:85.207.53.12

NS records: ns.web4u.cz, ns2.web4u.cz

🔒 DNSSEC Status

🔐 Secure (DNSSEC validated)

Chain of trust verified from root to domain

⏱️ Timing

Total: 744ms | Queries: -

📄 Records

Type	Count	Sample Data
A	1	`81.91.86.13`
AAAA	1	`2001:1568::13`
NS	2	`ns.web4u.cz, ns2.web4u.cz`
MX	2	`mx1.mailchannels.net (pri: 10), mx2.mailchannels.net (pri: 10)`
SOA	1	`ns.web4u.cz admin.web4u.cz`

📌 Glue Records Collected

Total: 4

Out-of-bailiwick: 4 (ns.web4u.cz, ns.web4u.cz, ns2.web4u.cz...)

Analysis

Hierarchy

cfrent.cz is the parent of mail.cfrent.cz.

IP Addresses

cfrent.cz resolves to two IP numbers: 2001:1568::13 and 81.91.86.13.

other host names including letni-tabory.com, mail.archibald.cz, czech-chinese-joint-chamber.com, vertikon.cz and software4cnc.com share IP numbers with cfrent.cz.

Name Servers

cfrent.cz is delegated to two name servers ns2.web4u.cz and ns.web4u.cz.

cfrent.cz shares the same name server setup as other domains, for instance a7b.cz, pcservishradubice.cz, autobahn.cz, prestigepools.cz and edumaster.cz.

Host names with two IP numbers:

The host name ns2.web4u.cz points to 2a02:a40:100:28ff::12 and 85.207.53.12; the host name ns.web4u.cz points to 2001:1568:fd::241 and 185.14.224.241.

Mail Servers

Two mail servers handle cfrent.cz: mx1.mailchannels.net and mx2.mailchannels.net.

cfrent.cz shares the same mail server setup as other domains, for instance winkies.org, eleutheradirect.com, cabrillo67-72.com, designverb.com and mail.jenkinsbrush.com.

cfrent.cz shares some mail servers with other domains, at least partially, for example dora.dk and vebu.co.uk.

Host names with a single IP:

mx1.mailchannels.net points to 54.187.177.89.

mx2.mailchannels.net points to 54.187.177.89.

Host names pointing to 54.187.177.89: mx1.mailchannels.net and mx2.mailchannels.net.

cfrent.cz - robtex.com

cfrent.cz

cz