When you make changes to your zone, you are making changes to the host. A resolver is a DNS server that will send requests to other DNS servers for the records from their zones to answer the requests that it receives.
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. How to Respond to Negative Reviews? How to Merge Two Facebook Pages? If you have purchased a new domain name or you have changed the name servers from one server to another server, you should expect a delay until you see the new website. This article will provide you some background information on DNS and what to expect when changing your name servers.
Name server changes usually take 24 to 48 hours to fully start working. Because of propagation, not all visitors will be directed to your new name servers on your new hosting account; some visitors will continue to be directed to your old name servers on your old hosting account until propagation is complete. How quickly visitors are directed to the new name servers depends on their physical location, internet service provider, how soon their router, devices cache gets refreshed, and some luck; it is not something you have control over.
Once propagation is complete, your site will appear on our server and your email will be fully functional. There is no definitive way to tell when propagation is complete. During the first 48 hours, even if you are able to see your site on the new server, your next-door neighbor might still be seeing the site on the old server. The routing of all communication between computers on the internet is handled by IP address rather than domain names.
The following example should help you to visualize the process. Similar to our telephone system, every active phone line has a phone number that is used to facilitate the connection of one line to another. In order to make a call, the phone that initiates the connection must have the number of the line to which it wants to connect. In much the same way, your computer must find the correct IP address of the website you want to visit on the server before it can send the request to that server for a webpage.
The same process applies to all other services such as email, chat, or games on the internet. DNS records function similar to a phone book, relating domain names with IP addresses so that these services can be reached.
DNS hosts hold the zones for their domains and answer requests with the records from the zones for those domains. When you make changes to your zone, you are making changes to the host. Collectives on Stack Overflow. Learn more. Why does updating a domain's nameservers take so long? Asked 9 years, 11 months ago. Active 3 years, 3 months ago. Viewed 50k times. Improve this question.
BronzeByte BronzeByte 1 1 gold badge 7 7 silver badges 11 11 bronze badges. I'm having a. For my requests they promised responses in 24 hour but missed all the times Add a comment. Active Oldest Votes. Some of the more remote locations take longer. Good luck! The Wikipedia article has an excellent writeup on this subject. Individual applications may not see the change within the TTL because of local DNS caches within routers, firewalls, operating systems and applications.
As mentioned in the Wikipedia article: "These caches typically use very short caching times — on the order of one minute. 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.
If you can't change your A records directly, then whatever application makes the changes control panel software, for example may introduce its own delays. We use a default TTL of 4 hours. If we are planning to change an A record, we lower the A record's TTL to 5 minutes must be done more than 4 hours before the change is to go into place. After the change has been made, we put the TTL back to 4 hours. Most applications see the change right away, but a few users will call in with problems and need to reboot.
The Wikipedia article also has a good discussion on "propagation": "Many people incorrectly refer to a mysterious 48 hour or 72 hour propagation time when you make a DNS change.
You can see these TTL values for yourself with the nslookup command. I always tell my users it'll be 48 hours for full propagation, to compensate for all the issues mentioned above. Besides the TTL something that you control, see Brian Clapper's excellent advice , and possible longer caching times inside some applications, there is also the synchronization time between the authoritative name servers.
If you're talking Windows and you're talking internal, it depends on the original TTL. When we knew ahead of time that we were going to make a change, we would set the TTL on the A record low Then once the change was made, we increased the TTL back to a more normal amount.
If you're talking about on the Internet, all bets are off. There are some caching domain controllers that we have seen completely ignore TTL, as already mentioned. In those cases we've gone with a general rule of 48 hours. I've seen on average hours for most people.
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