sofsem.org - dns.ninja
sofsem.org
| DNSSEC | ⚠️ Not signed | ||||||
| A | 147.231.6.218🇨🇿 CESNET147.231.0.0/16 | ||||||
| NS | fw.cs.cas.cz ⭐ ⚠️ Not in zone NS records | ||||||
| A | 147.231.6.1🇨🇿 CESNET147.231.0.0/16 | ||||||
| NS | fw.cas.cz ⚠️ Not in parent delegation | ||||||
| NS | ns2.ignum.cz ⚠️ Not in parent delegation | ||||||
| A | 2001:1ab0:7e1e:2::5🇨🇿 IGNUM-AS2001:1ab0::/32 Network of Ignum s.r.o. Czech Republic http://www.ignum.cz/ | ||||||
| PTR | ns2-prg.core.webglobe.com | ||||||
| A | 217.31.48.201🇨🇿 IGNUM-AS217.31.48.0/20 Network of Ignum s.r.o. Czech Republic http://www.ignum.cz/ | ||||||
| PTR | ns2-prg.core.webglobe.com | ||||||
| NS | visla.utia.cas.cz | ||||||
| A | 2001:718:401:1::1🇨🇿 CESNET2001:718::/32 6-TCZ | ||||||
| PTR | visla.utia.cas.cz | ||||||
| A | 147.231.12.1🇨🇿 CESNET147.231.0.0/16 | ||||||
| PTR | visla.utia.cas.cz | ||||||
| MX | mgw.cs.cas.cz ⭐ | ||||||
| SOA | fw.cs.cas.czhostmaster@cas.cz 2026-05-18 #0 | ||||||
org
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a0.org.afilias-nst.info ⭐ ⚠️ Not in parent delegation | ||||||
| NS | a2.org.afilias-nst.info ⚠️ Not in parent delegation | ||||||
| NS | b0.org.afilias-nst.org | ||||||
| NS | b2.org.afilias-nst.org | ||||||
| NS | c0.org.afilias-nst.info ⚠️ Not in parent delegation | ||||||
| NS | d0.org.afilias-nst.org | ||||||
| SOA | a0.org.afilias-nst.infohostmaster@donuts.email serial=1788028141 | ||||||
Previously MX for
sofsem.org |
Same first word
Similar names
fomess.com |
fmsseo.com |
fesmos.ru |
mfosse.be |
sofmes.com |
smfseo.com |
fmoses.de |
seomfs.com |
femoss.blogspot.com |
mfosse.ca |
fmoses.com |
msfeso.com |
fmosse.workers.dev |
smfseo.net |
sofems.org |
mfosse.com |
Previous names
Next names
DNS History
17 records (6 active, 11 former)
○NSdns100.ovh.net2015-06-20 → 2015-06-20 · 3 obs
○ 2015-11-09 11:52:48
○ 2026-08-29 18:52:50
●NSfw.cas.cz2026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
●NSfw.cs.cas.cz2026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
○NSns1.dnsdun.net2017-05-19 → 2017-05-19 · 4 obs
● 2017-05-19 23:44:30
○ 2026-08-18 14:15:26
○ 2026-08-29 18:52:50
○NSns1.gamez7.com2015-11-09 → 2015-11-09 · 4 obs
● 2015-11-09 11:52:48
○ 2016-09-20 11:00:56
○ 2026-08-29 18:52:50
○NSns100.ovh.net2015-06-20 → 2015-06-20 · 3 obs
○ 2015-11-09 11:52:48
○ 2026-08-29 18:52:50
○NSns2.gamez7.com2015-11-09 → 2015-11-09 · 4 obs
● 2015-11-09 11:52:48
○ 2016-09-20 11:00:56
○ 2026-08-29 18:52:50
●NSns2.ignum.cz2026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
○NSns3.dnsdun.com2017-05-19 → 2017-05-19 · 4 obs
● 2017-05-19 23:44:30
○ 2026-08-18 14:15:26
○ 2026-08-29 18:52:50
●NSvisla.utia.cas.cz2026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
●MXmgw.cs.cas.cz2026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
○MXredirect.ovh.net2015-06-20 → 2015-06-20 · 3 obs
○ 2015-11-09 11:52:48
○ 2026-08-29 18:52:50
○MXsofsem.org2015-11-09 → 2015-11-09 · 4 obs
● 2015-11-09 11:52:48
○ 2016-09-20 11:00:56
○ 2026-08-29 18:52:50
○A104.171.182.2032017-05-19 → 2017-05-19 · 4 obs
● 2017-05-19 23:44:30
○ 2026-08-18 14:15:26
○ 2026-08-29 18:52:50
●A147.231.6.2182026-08-18 → 2026-08-29 · 3 obs
● 2026-08-18 14:15:26
● 2026-08-29 18:52:50
○A213.186.33.42015-06-20 → 2015-06-20 · 3 obs
○ 2015-11-09 11:52:48
○ 2026-08-29 18:52:50
○A67.222.15.1262015-11-09 → 2015-11-09 · 4 obs
● 2015-11-09 11:52:48
○ 2016-09-20 11:00:56
○ 2026-08-29 18:52:50
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| org | b2.org.afilias-nst.org, b0.org.afilias-nst.org, d0.org.afilias-nst.org | - |
| sofsem.org | visla.utia.cas.cz, fw.cs.cas.cz | - |
✅ Authoritative Response
Server:147.231.12.1
NS records: visla.utia.cas.cz, fw.cs.cas.cz
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for sofsem.org (unsigned zone)
⏱️ Timing
Total: 1351ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 147.231.6.218 |
| NS | 3 | fw.cas.cz, visla.utia.cas.cz... |
| MX | 1 | mgw.cs.cas.cz (pri: 5) |
| SOA | 1 | fw.cs.cas.cz hostmaster.cas.cz |
Analysis
IP Addresses
sofsem.org has exactly one IP address — 147.231.6.218.
shinyitemanalysis.org, cs.cas.cz, ustavinformatiky.cz plus two other host names have IP numbers in common with sofsem.org.
Name Servers
Four name servers handle the delegation for sofsem.org: fw.cas.cz, ns2.ignum.cz, fw.cs.cas.cz and visla.utia.cas.cz.
sofsem.org shares at least some of its name servers with other domains, including barth-eshop.cz, webdiar.cz, chalupybroumovsko.cz and two others.
These name servers are frequently seen alongside ns1.ignum.com, academy.cas.cz, nsa.ces.net and 4 other name servers.
Host names pointing to two IP addresses:
ns2.ignum.cz maps to two IP addresses — 217.31.48.201 and 2001:1ab0:7e1e:2::5.
visla.utia.cas.cz maps to two IP addresses — 147.231.12.1 and 2001:718:401:1::1.
Host names resolving to a single IP address:
fw.cs.cas.cz points to the IP address 147.231.6.1.
Mail Servers
sofsem.org uses one mail server — mgw.cs.cas.cz.
The mail server setup of sofsem.org matches that of other domains such as informatics.cz, cs.cas.cz, uivt.cas.cz and two others.