Dynamic IP: Technical Details
OpenDNS accounts work with dynamic IP addresses through Dynamic DNS (DDNS), if you use a DDNS software client. (See sidebar for software information, or go to the downloads page.) For OpenDNS, the purpose of dynamic DNS is to preserve your OpenDNS preferences if your ISP or network operator changes your IP address.
What is dynamic DNS?
Many people get a dynamic Internet Protocol (IP) address assigned to them by their ISP or network operator. It is difficult for public Internet resources to know how to find a webserver or mailserver or other Internet-addressable resource located at a dynamic IP address. DDNS provides a workaround, giving an individual a method of registering their current IP address with a third-party service on the web so they are publicly accessible and addressable, even as their IP address changes over time.
The below information still holds true, but DNS-O-Matic, a free service from OpenDNS, gives you an easy way to distribute your dynamic IP changes to multiple services with a single update. Keep dynamic DNS hostnames and OpenDNS updated at the same time.
OpenDNS Dynamic DNS FAQ
OpenDNS provides a tool called fetchstats to enable OpenDNS Administrators to download the Top Domains log data that has been collected for a network. Fetchstats is useful when downloading data ranges that are greater than 200 records, which is the file-size limit for an online download from the OpenDNS Stats page.
The fetchstats tool is available for Linux and Microsoft operating systems and both use the following arguments:
- <username> - the email address of the OpenDNS Administrator for the network
- <network-id> - the numerical id of network; found in URL of network’s Dashboard settings page
- <YYYY-MM-DD> - the first day of the report
- [<YYYY-MM-DD>] - the optional last day of the report
For more information about using fetchstats, click or copy one of the following links:
To download the fetchstats tool click on or copy one of the following links:
Note: The OpenDNS password for the network being accessed is required to access fetchstats and to proceed with the data download.
Fetchstats is made available by OpenDNS, but is not directly supported. Use of the tool is at your own risk.
If you have received one of the following Error Messages while navigating the Internet or using OpenDNS, expand the message to understand the cause of the error and the known solutions to resolve it.
You can find and download the official Dynamic IP updater clients for Windows, Mac and Linux using the links in the following table. There are additional third-party clients and services available, but only the ones listed are supported by OpenDNS.
|OpenDNS Dynamic IP |
Address Updater Client
|Windows IP Updater||This is the officially supported OpenDNS Windows client, which sends your network's new IP Address to OpenDNS whenever it should change.|
|Mac IP Updater||This is the officially supported OpenDNS Mac client, which sends your network's new IP Address to OpenDNS whenever it should change.|
|Linux IP Updater||This links to the officially supported OpenDNS Linux client, which sends your network's new IP Address to OpenDNS whenever it should change.|
OpenDNS can be configured on networks that are provisioned with dynamic IP addresses, which is typically how ISPs manage consumer and small business networks.
Please read Networks with Dynamic IP Addresses to learn how to maintain OpenDNS settings on a network where the IP address is likely to change.
The following table explains the DNS Request Types that can be collected and listed in an OpenDNS report.
|DNS Lookup Type||Description||Function|
|A||IPv4 address record||Returns a 32-bit IP address, which typically maps a domain's hostname to an IP address, but also used for DNSBLs and storing subnet masks|
|AAAA||IPv6 address record||Returns a 128-bit IP address that maps a domain's hostname to an IP address|
|MX||Mail exchange record||Maps a domain name to a list of message transfer agents for that domain|
|NS||Name server record||Delegates a DNS zone to use the specified authoritative name servers|
|PTR||Pointer record||Pointer to a canonical name that returns the name only and is used for implementing reverse DNS lookups|
|SOA||Start of authority record||Specifies authoritative information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone|
|SRV||Service locator||Generalized service location record, used for newer protocols instead of creating protocol-specific records such as MX|
|TXT||Text record||Carries extra data, sometimes human-readable, most of the time machine-readable such as opportunistic encryption, DomainKeys, DNS-SD, etc.|
SmartCache - Here's how it works: When an authoritative DNS provider suffers an outage, all of the Websites it provides service for are taken offline. They are inaccessible for everyone on the Internet. But no longer for OpenDNS users. Our servers will now immediately look for the last known good address for the site in our caches, and use that to load the site. So effectively OpenDNS users will be able to access Websites that appear down for everyone else. For our millions of users at businesses, schools and libraries around the world, saving them Internet access interruptions and the time they waste is invaluable.
Authoritative DNS outages happen frequently and can be a big problem. In March of 2009, it was reported that major authoritative DNS provider UltraDNS suffered an outage that took Salesforce.com, Amazon.com and Petco.com offline for several hours. In such a case, SmartCache fixes the inaccessibility problem and allows people to visit those sites despite the authoritative server outage.
This is just the latest in a long series of DNS innovations we've developed and passed on to you. Most recently it was blocking the Conficker worm from phoning home. By blocking the domain names the worm used, we were and continue to be able to protect people around the globe. We want our customers to know that we are committed to continually innovate and give you easy-to-use services that make your Internet experience better.
SmartCache is turned on by default for all users and only applies to queries where the authoritative server hands back a SERVFAIL response code or the query simply goes unanswered.