What is TTL (Time To Live)?
Time To Live (TTL) is a networking parameter used in TCP/IP to limit how long data packets can travel across a network. Each router decreases the TTL value by one hop. When TTL reaches zero, the packet is discarded to prevent infinite routing loops.
In DNS, TTL defines how long a DNS record is cached by resolvers before refreshing. Lower TTL values allow faster DNS propagation updates, while higher values improve caching efficiency.
Why Use a TTL Calculator?
- Convert TTL seconds into minutes and hours
- Analyze DNS propagation timing
- Understand packet routing behavior
- Work with IPv4 TTL and IPv6 hop limit
Frequently Asked Questions
What is a normal TTL value?
Common DNS TTL values range from 300 to 86400 seconds depending on caching needs.
Does TTL affect DNS propagation?
Yes. TTL controls how long DNS resolvers cache records before refreshing.
What does TTL expired mean?
It indicates a packet exceeded its hop limit and was dropped to avoid routing loops.