How long change dns

These sorts of requests are called recursive requests. When you connect to the internet through your Internet Service Provider ISP , your ISP will provide you with two or more resolvers responsible for handling the recursive DNS requests sent by your computer as you use the internet. Since most DNS records don't change very often, most resolvers are configured to cache or store the results of previous lookups and respond to subsequent requests from the cached results for a period of time until the resolver decides that the cached copy is too old to be trusted.

Propagation is the period it takes for the record cached on all resolvers everywhere to expire. One technique to reduce the time it takes for changes to propagate is to reduce the TTL value in the current zone before making changes; however, the change in the TTL on the record itself will take the length of time specified in the original TTL value to propagate before propagation period is lowered for further changes.

Also, some ISPs configure their resolvers to ignore the TTL value specified in the record altogether and cache the record for a length of time that they specify instead. Some resolvers are configured to cache records for up to 72 hours, although most are configured less.

Ultimately, time resolves propagation issues. DNS records are maintained on DNS servers, and, like the names, the servers are organised hierarchically. The PC on your desk, your tablet, your phone, they all need to know how to find a DNS server, and they are typically told that as part of the network configuration of the device. When your phone asks for the address of bbc. Originally, mail too was handled by the server with the corresponding A record address, but as time went on it became desirable to separate out mail handling.

Enter the MX Mail Exchanger record. The MX record for a domain holds the name not IP address of one or more servers that will accept mail on behalf of that domain. So, the DNS records for the bbc.

This question is probably a better fit over at ServerFault. I know that wasn't up when this question was asked, but ou maybe get the answer you need there Add a comment. Active Oldest Votes. Improve this answer. Community Bot 1. David Spillett David Spillett Sorry, I probably shouldn't have use social acronyms in amongst technical ones!

IIRC is "if I recall correctly". Brian Rasmussen Brian Rasmussen 2 2 silver badges 5 5 bronze badges. Brian Clapper Brian Clapper 1 1 silver badge 4 4 bronze badges. Mike Mike 1 1 gold badge 6 6 silver badges 7 7 bronze badges. John Virgolino John Virgolino 8 8 silver badges 17 17 bronze badges. Internet Explorer offers a notable exception: recent versions cache DNS records for half an hour" A reboot or power cycle for routers will typically flush all local DNS caches, but obviously you can't expect every user out there to reboot every device after you change your A record.

Tezza P. Tezza 2 2 bronze badges. RainyRat RainyRat 3, 1 1 gold badge 22 22 silver badges 28 28 bronze badges. So, to emphasize Brian Clapper's advice: plan in advance. Brian Kelley K. Brian Kelley 8, 30 30 silver badges 33 33 bronze badges.

Zypher Zypher JoshBerke JoshBerke 2 2 silver badges 8 8 bronze badges. The sad but true answer depends on who's asking for your DNS answers. Every time you use a domain name on your computer its DNS information will be stored in the cache. Even if a record is changed, DNS servers will continue working with its formal value from cache until this time has passed. This is the essence of DNS propagation — it is the time required for DNS servers worldwide to update their cached information for a domain name.

It is influenced by the TTL of DNS records that might have changed, but there are also other factors that could come into play.