Network diagnostics · UNC Information Technology Services
DNS Lookup
Compare the campus DNS view with the public Internet view. TTL values show approximately how long each resolver may keep an answer cached before refreshing it.
Answer comparison
| DNS answer | Campus DNS TTL | Internet DNS TTL | Comparison |
|---|
TTLs are the remaining cache lifetimes reported by each recursive resolver, so they may differ even when the answers match.
What this DNS lookup tool checks
Use this tool to look up the records that publish a domain's addresses, aliases, mail servers, name servers, verification data, and other DNS configuration. It reports each answer's remaining cache lifetime (TTL), response status, and query time.
Supported DNS record types
- A and AAAA — IPv4 and IPv6 addresses for a domain name
- CNAME — aliases that point one name to another
- MX — mail servers responsible for receiving email
- TXT — text records commonly used for domain verification and email security
- NS and SOA — authoritative name servers and DNS zone information
- PTR — reverse DNS lookup from an IPv4 or IPv6 address to a host name
Campus and public DNS comparison
From the UNC campus network or VPN, the same lookup is sent to the campus and public resolvers. Comparing their answers can reveal split-horizon DNS, cache differences, or records available only inside the campus network. Off campus, the tool shows the public Internet DNS view.