Remember PTR
Full name: Pointer record
Memory aid: A PoinTeR points back to a name.
Reverse DNS does not prove ownership or trustworthiness of a service.
Study area: Protocols & logical ports · Batch 7
Relevant study for: CompTIA Network+ N10-009 · Cisco CCNA 200-301 · CompTIA A+ Core 1 220-1201 · CompTIA Security+ SY0-701 · ISC2 CISSP 2024 outline
Practice with exam flashcards →Networking & Connectivity / Knowledge library
PTR — Pointer record
Maps a DNS name to another name, commonly for reverse-address lookup.
Why learn PTR — Pointer record?
Maps a DNS name to another name, commonly for reverse-address lookup.
Where it came from
Reverse DNS does not prove ownership or trustworthiness of a service.
- Memory aid (a learning cue, not the expansion): A PoinTeR points back to a name.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Without looking, expand PTR: Pointer record.
- Recall this memory aid: A PoinTeR points back to a name.
- Explain the practical use: Maps a DNS name to another name, commonly for reverse-address lookup.
- Explain this distinction: Reverse DNS does not prove ownership or trustworthiness of a service.
- Identify PTR in a device specification, architecture diagram, or system inventory.
Documentation and sources
- IETF RFC 1035 (www.rfc-editor.org)