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Zorluk: OrtaDNS Infrastructure and Record Types

A network administrator executes the following `dig` commands from a diagnostic workstation to verify DNS records for a newly deployed VoIP gateway operating at IP address `192.168.10.50`:

text
$ dig +short SRV _sip._udp.corp.example.com
10 60 5060 voice01.corp.example.com.

$ dig +short -x 192.168.10.50
voice01.corp.example.com.

Based on the output provided above, which TWO of the following DNS record types are returning active, authoritative information for this gateway?

  1. SRV recordCevap
  2. PTR recordCevap
  3. C
    CNAME record
  4. D
    MX record
  5. E
    TXT record

Cevap

The correct responses are the SRV record and the PTR record.
The output demonstrates two distinct DNS query types. The first command explicitly queries the SRV record to locate the SIP service port and server hostname. The second command uses the reverse lookup option (-x) to query the PTR record corresponding to IP 192.168.10.50, returning the canonical hostname.

Adım Adım Çözüm

1
Analyze the first command input and returned data.
The command `dig +short SRV _sip._udp.corp.example.com` explicitly queries for an SRV (Service Location) record. The output returns port `5060` and hostname `voice01.corp.example.com`.
SRV records define symbolic names, transport protocols (UDP), port numbers, and hostnames for protocol-specific services like SIP or LDAP.
2
Analyze the second command input and returned data.
The command `dig +short -x 192.168.10.50` performs a reverse DNS lookup for IPv4 address `192.168.10.50`, returning `voice01.corp.example.com.`.
Reverse DNS resolution queries the `in-addr.arpa` domain using PTR (Pointer) records to resolve IP addresses back to domain names.

Anahtar Kavram

DNS SRV and PTR Resource Records
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Konular

DNS Infrastructure and Record Types

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