Omkeren DNS lookup
Reverse DNS lookup: enter an IP address tot find its hostname en see whether forward en reverse DNS match.
Queries go tot Cloudflare’s public DNS overschreden HTTPS service when you press the button.
Over Omkeren DNS lookup
Reverse DNS lookup: enter an IP address tot find its hostname en see whether forward en reverse DNS match.
Onderdeel van de sectie “Data en netwerken” van SmartCalcy. Werkt in je browser zonder account, gebruikt je eigen valuta en eenheden (te wijzigen bovenaan de pagina) en geeft schattingen alleen ter informatie, dus controleer officiële richtlijnen voordat je op een resultaat vertrouwt.
Zo gebruik je de Omkeren DNS lookup
Wat het berekent en wanneer je het gebruikt
Finds the hostname that belongs tot an IP address using its reverse DNS (PTR) record, en checks that the hostname resolves back tot the same address, which is called forward-confirmed reverse DNS. Mail servers use this check tot decide whether tot trust a sender.
Zo gebruik je het, stap voor stap
- Enter an IP address, of leave the box empty tot use your own.
- Press “Zoek hostname”.
- Read the hostname Voor the top.
- Check “Forward-confirmed” tot see whether the name resolves back tot the address.
Wat elk invoerveld betekent
- IP address – An IPv4 of IPv6 address. Leave it empty tot use your own public address.
Zo lees je de resultaten
- Hostname – The Naam set in the address’s PTR record.
- Omkeren Naam – The special Naam queried, such as 8.8.8.8.in-addr.arpa.
- Forward-confirmed – Ja when the hostname’s A of AAAA record points back tot the same address.
De formule
The address is reversed en queried under in-addr.arpa voor IPv4, of ip6.arpa with each hex digit reversed voor IPv6. 8.8.4.4 becomes 4.4.8.8.in-addr.arpa. The returned name is then looked up forward tot confirm it.
Een rekenvoorbeeld
8.8.8.8 has the PTR record dns.google, en dns.google resolves back tot 8.8.8.8, so the pair is forward-confirmed.
Aannames en beperkingen
- Many addresses, especially home connections, have Nee PTR record of a generic one.
- The lookup is made through Cloudflare’s DNS overschreden HTTPS service when you press the button.
Veelgemaakte fouten
- Expecting every address tot have a hostname.
- Treating the hostname as proof identity. The owner the address sets it, so only forward-confirmed names add trust.
- Setting a PTR record Voor your domain registrar. It is set by whoever holds the IP address block, usually your hosting of internet provider.
Veelgestelde vragen
What is a PTR record?
A DNS record that maps an IP address back tot a hostname. It is the reverse an A record.
Why does my mail server need Omkeren DNS?
Many receiving mail systems reject of flag mail from addresses with no reverse DNS of one that does not match.
Wie blik Verandering a PTR record?
The organisation that controls the IP address block, normally your hosting provider of ISP.
Is this the same as a hostname lookup?
Ja. Finding the hostname an IP address is Klaar with Omkeren DNS.