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Thursday, March 27, 2008
Standard Dynamic DNS Domains
Wednesday, March 26, 2008
What is a Domain Registration?
A domain name is essentially online real estate, and domain registration provides temporary ownership over that real estate. Domain registrations are leased to the registrant in yearly increments, usually between one and ten years, and allow the registrant to "build" on this property by offering services such as websites, email and FTP for personal, commercial, or public use. DynDNS offers a Domain Registration service for users who would like to purchase a domain name.
Delegation
In addition to providing ownership, domain registrations hold the name server delegation for a domain. Delegation assigns DNS resolution duties to name servers, directing queries for the domain to its DNS provider. A domain requires both registration and DNS to function; a registered domain without DNS cannot tell people where to find web services, and a name server with DNS information about an unregistered domain has no authority or ability to resolve queries for that domain.
Despite being closely linked, DNS service and registration are not identical or interchangeable. In fact, DNS service and domain registration can be provided by separate entities. For example, if you have a domain registered with another company, you can still use our Custom DNS service by changing the delegation to use our name servers instead of theirs.
Delegation changes can be performed at any time; however, depending on the TLD of your domain, the delegation may not immediately take effect. (Please see the Domain Information Chart for further information on common TLDs and their delegation change delays.) Furthermore, some cached queries may continue to go to the old DNS provider for up to four days after a delegation change. To minimize potential downtime during a delegation change, please see our Changing DNS Providers Without Downtime article.
Glue Records
Before a new name server can be used, a glue record needs to be created for the name server at the registry. Glue records provide information on a name server, such as the IP address and responsible registrar, and prevent a chicken-and-egg problem with DNS resolution: without a glue record, it would not be possible to initially locate a name server to ask it for information about itself and the domains it serves.
If you have third-party DNS for your domain (such as our Custom DNS service), you will not need to create glue records, as your DNS provider already has glue records for their name servers. If you wish to provide DNS for your own domain using a DNS server application such as BIND, you can create glue records through your account's domain registration interface or by contacting your registrar to request glue records. You may also be interested in a Secondary DNS service to provide redundancy and stability for your domain's resolution.
Because glue records have high TTLs, changes to glue can take up to 48-96 hours to fully propagate, making it impractical or impossible to host DNS for a domain on a dynamic IP address.
Wednesday, March 19, 2008
ChangeIP.com Dynamic SMTP
Do you run your own mail server? Do you need a backup to your existing set of servers? Do you need to fix your ISPs blocked ports? If you answered yes to any of these questions then you need our Dynamic SMTP product. We can provide your domain names a backup mail server to collect mail in case yours cannot. A common mistake that is made is not having a secondary mail server to act as a backup in case the primary is not available.
Here are some of the features of Dynamic SMTP Store and Forward service:
- Alternate Port SMTP - Does your ISP block port 25 to or from your mail server? We can help! Just add a port number after the SmartHost and we'll deliver your email on another port.
- Redundancy - Our Dynamic SMTP service is a perfect solution to provide redundancy to your existing mail server(s). Adding an additional MX record to your domain gives you the comfort of knowing your mail won't be returned if your servers are down.
- Flexible Limits - Daily quotas can be increased/decreased using our online management console. You can configure each domain to have its own quota limits. This means that you can purchase 10MB or 500mb of space for whatever your needs may be. Our system tallies up the total amount of mail received per day and checks it against the quota on the domain.
- ETRN/ATRN - We can provide standard backup MX service where mail delivery is tried immediately. We can also provide ETRN/ATRN queuing if you would like.
- SPAM Filtering - Stop unwanted email before it even gets to your mailbox. We apply a highly effective RegEx filter to each email that arrives against a known dictionary of common spam words. If the email scores too high on the spam test it will be rejected before it even gets delivered. In our tests we typically reject 95% of unwanted email and 0.1% of good email - now that's amazing! The level of spam filtering can be configured for each account individually using our online management console.
- AntiVirus Scanning - Using the award winning McAfee engine we scan all parts of an email to consistently deliver virus-free emails. No more worrying if there are any harmful emails waiting to erase your computer or embarrass you by sending out your private information to all your friends. Virus scanning can be configured for each account individually using our online management console.
Why choose ChangeIP.com Dynamic SMTP as your mail server backup solution?
- Full-featured - Designed and maintained by world class engineers, the ChangeIP mail platform offers an unparalleled combination of features and technology. Features such as Spam filtering, virus scanning, Web Mail, alternate port access, and unlimited storage can help you or your employees stay focused on more important things.
- Cost Effective - Top quality SMTP service doesn't have to be complicated or expensive. ChangeIP.com Dynamic SMTP eliminates the single point of failure when only 1 mail server exists. In fact, ChangeIP.com Dynamic SMTP can cost a fraction of what you would normally spend on an in-house backup solution.
- Reliable - The ChangeIP.com Email system has thousands of satisfied customers and delivers millions of emails every month. With ChangeIP.com Dynamic SMTP, expect reliability and scalability, no matter what your specific needs are. Our email systems are monitored 24 hours a day, 7 days a week, by staff that is committed and trained to provide you with superior monitoring and reliability assurance.
Friday, March 14, 2008
DNS works in theory
Short for dynamic Domain Name System, a method of keeping a domain name linked to a changing IP address as not all computers use static IP addresses. Typically, when a user connects to the Internet, the user's ISP assigns an unused IP address from a pool of IP addresses, and this address is used only for the duration of that specific connection. This method of dynamically assigning addresses extends the usable pool of available IP addresses. A dynamic DNS service provider uses a special program that runs on the user's computer, contacting the DNS service each time the IP address provided by the ISP changes and subsequently updating the DNS database to reflect the change in IP address. In this way, even though a domain name's IP address will change often, other users do not have to know the changed IP address in order to connect with the other computer.
How DNS works in theory
The domain name space
The domain name space consists of a tree of domain names. Each node or leaf in the tree has one or more resource records, which hold information associated with the domain name. The tree sub-divides into zones. A zone consists of a collection of connected nodes authoritatively served by an authoritative DNS nameserver. (Note that a single nameserver can host several zones.)
When a system administrator wants to let another administrator control a part of the domain name space within his zone of authority, he can delegate control to the other administrator. This splits a part of the old zone off into a new zone, which comes under the authority of the second administrator's nameservers. The old zone ceases to be authoritative for what goes under the authority of the new zone
DNS servers
The Domain Name System consists of a hierarchical set of DNS servers. Each domain or subdomain has one or more authoritative DNS servers that publish information about that domain and the name servers of any domains "beneath" it. The hierarchy of authoritative DNS servers matches the hierarchy of domains. At the top of the hierarchy stand the root nameservers: the servers to query when looking up (resolving) a top-level domain name (TLD).
DNS resolvers
A resolver looks up the resource record information associated with nodes. A resolver knows how to communicate with name servers by sending DNS queries and heeding DNS responses.
A DNS query may be either a recursive query or a non-recursive query:
- A non-recursive query is one where the DNS server may provide a partial answer to the query (or give an error). DNS servers must support non-recursive queries.
- A recursive query is one where the DNS server will fully answer the query (or give an error). DNS servers are not required to support recursive queries.
The resolver (or another DNS server acting recursively on behalf of the resolver) negotiates use of recursive service using bits in the query headers.
Resolving usually entails iterating through several name servers to find the needed information. However, some resolvers function simplistically and can only communicate with a single name server. These simple resolvers rely on a recursive query to a recursive name server to perform the work of finding information for them.
DDNS
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