istudycalculus.com - robtex.com
istudycalculus.com
| DNSSEC | ⚠️ Not signed | ||||||
| A | 192.243.85.36🇺🇸 F5192.243.85.0/24 hosted | ||||||
| NS | pdns85.ultradns.com ⭐ | ||||||
| A | 2001:502:f3ff::79🇺🇸 MAINT-ID-120082001:502:f3ff::/48 Neustar | ||||||
| PTR | pdns85.ultradns.com | ||||||
| A | 156.154.64.85🇺🇸 MAINT-ID-12008156.154.64.0/24 Neustar | ||||||
| PTR | pdns85.ultradns.com | ||||||
| NS | pdns85.ultradns.biz | ||||||
| A | 2610:a1:1015::79🇺🇸 MAINT-ID-120082610:a1:1015::/48 Neustar | ||||||
| PTR | pdns85.ultradns.biz | ||||||
| A | 156.154.66.85🇺🇸 MAINT-ID-12008156.154.66.0/24 Neustar | ||||||
| PTR | pdns85.ultradns.biz | ||||||
| NS | pdns85.ultradns.net | ||||||
| A | 2610:a1:1014::79🇺🇸 MAINT-ID-120082610:a1:1014::/48 Neustar | ||||||
| PTR | pdns85.ultradns.net | ||||||
| A | 156.154.65.85🇺🇸 MAINT-ID-12008156.154.65.0/24 Neustar | ||||||
| PTR | pdns85.ultradns.net | ||||||
| NS | pdns85.ultradns.org | ||||||
| A | 2001:502:4612::79🇺🇸 MAINT-ID-120082001:502:4612::/48 Neustar | ||||||
| PTR | pdns85.ultradns.org | ||||||
| A | 156.154.67.85🇺🇸 MAINT-ID-12008156.154.67.0/24 Neustar | ||||||
| PTR | pdns85.ultradns.org | ||||||
| MX | corp148mr3.mcgraw-hill.com ⭐ | ||||||
| MX | corp148mr4.mcgraw-hill.com ⭐ | ||||||
| MX | nj12corpmr01.mcgraw-hill.com ⭐ | ||||||
| MX | nj12corpmr02.mcgraw-hill.com ⭐ | ||||||
| TXT | v=spf1 mx -all | ||||||
| SOA | pdns85.ultradns.comhostmaster@mheducation.com 2014-06-30 #17 | ||||||
com
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a.gtld-servers.net ⭐ | ||||||
| NS | b.gtld-servers.net | ||||||
| NS | c.gtld-servers.net | ||||||
| NS | d.gtld-servers.net | ||||||
| NS | e.gtld-servers.net | ||||||
| NS | f.gtld-servers.net | ||||||
| NS | g.gtld-servers.net | ||||||
| NS | h.gtld-servers.net | ||||||
| NS | i.gtld-servers.net | ||||||
| NS | j.gtld-servers.net | ||||||
| NS | k.gtld-servers.net | ||||||
| NS | l.gtld-servers.net | ||||||
| NS | m.gtld-servers.net | ||||||
| SOA | a.gtld-servers.netnstld@verisign-grs.com serial=1777382941 | ||||||
Same first word
istudycalculus.com |
istudycalculus.ca |
DNS History
11 records (9 active, 2 former)
●NSpdns85.ultradns.biz2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●NSpdns85.ultradns.com2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●NSpdns85.ultradns.net2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●NSpdns85.ultradns.org2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●MXcorp148mr3.mcgraw-hill.com2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●MXcorp148mr4.mcgraw-hill.com2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●MXnj12corpmr01.mcgraw-hill.com2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
●MXnj12corpmr02.mcgraw-hill.com2015-08-18 → 2026-04-28 · 2 obs
● 2026-04-28 13:42:22
○A192.243.83.302015-08-18 → 2017-03-22 · 4 obs
● 2017-03-22 23:09:12
○ 2026-04-24 09:55:54
○ 2026-04-28 13:42:22
●A192.243.85.362026-04-24 → 2026-04-28 · 3 obs
● 2026-04-24 09:55:54
● 2026-04-28 13:42:22
○A192.243.93.452015-08-18 → 2017-03-22 · 4 obs
● 2017-03-22 23:09:12
○ 2026-04-24 09:55:54
○ 2026-04-28 13:42:22
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| com | b.gtld-servers.net, k.gtld-servers.net, f.gtld-servers.net, e.gtld-servers.net... | - |
| istudycalculus.com | pdns85.ultradns.net, pdns85.ultradns.com, pdns85.ultradns.biz, pdns85.ultradns.org | 2 records |
✅ Authoritative Response
Server:156.154.67.85
NS records: pdns85.ultradns.net, pdns85.ultradns.com, pdns85.ultradns.biz, pdns85.ultradns.org
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for istudycalculus.com (unsigned zone)
⏱️ Timing
Total: 881ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 192.243.85.36 |
| NS | 4 | pdns85.ultradns.biz, pdns85.ultradns.com... |
| MX | 4 | corp148mr3.mcgraw-hill.com (pri: 20), corp148mr4.mcgraw-hill.com (pri: 20)... |
| TXT | 1 | v=spf1 mx -all |
| SOA | 1 | pdns85.ultradns.com hostmaster.mheducati |
📌 Glue Records Collected
Total: 2
Out-of-bailiwick: 2 (pdns85.ultradns.com, pdns85.ultradns.com)
Analysis
IP Addresses
istudycalculus.com resolves to a single IP address: 192.243.85.36.
Other host names including istudycriminaljustice.com, istudyfinance.ca, istudyaccounting.ca, mcgraw-hill-ryerson.com and wncpmathcurriculum.com share IP numbers with istudycalculus.com.
Name Servers
istudycalculus.com is delegated to four name servers: pdns85.ultradns.biz, pdns85.ultradns.com, pdns85.ultradns.net and pdns85.ultradns.org.
istudycalculus.com at least partially shares name servers with other domains, including mhrln.com, connectmktg.net, gfienergy.com, acepmemberoffer.com and revealmath.com.
Hosts with two IP numbers:
Host pdns85.ultradns.biz points to 2610:a1:1015::79 and 156.154.66.85
Host pdns85.ultradns.com points to 2001:502:f3ff::79 and 156.154.64.85
Host pdns85.ultradns.net points to 2610:a1:1014::79 and 156.154.65.85
Host pdns85.ultradns.org points to 2001:502:4612::79 and 156.154.67.85
Mail Servers
istudycalculus.com is served by four mail servers: corp148mr3.mcgraw-hill.com, corp148mr4.mcgraw-hill.com, nj12corpmr01.mcgraw-hill.com and nj12corpmr02.mcgraw-hill.com.
The mail servers for istudycalculus.com are shared with other domains, for instance istudynutrition.ca, standardandpoors.lt, istudybusstats.ca, standardandpoors.us and istudycomposition.com.
These mail servers are commonly used alongside corp148mr6.mcgraw-hill.com and corp55wmr5.mcgraw-hill.com.