Difference between revisions of "DNS"
| Line 20: | Line 20: | ||
These servers are for pure redundancy. You can have many other DNS servers for your connections. Typically these servers are typically offsite, whereas our DNS servers are onsite. If both XMissions Primary and Secondary DNS servers go down, thats when these DNS servers will kick in. Popular providers for this kind of service is OpenDNS and Google's Public DNS. | These servers are for pure redundancy. You can have many other DNS servers for your connections. Typically these servers are typically offsite, whereas our DNS servers are onsite. If both XMissions Primary and Secondary DNS servers go down, thats when these DNS servers will kick in. Popular providers for this kind of service is OpenDNS and Google's Public DNS. | ||
| − | + | ==DNS Caching== | |
| − | DNS | + | ===Overview=== |
| + | A DNS cache is a local database copy of all domain names translated to IP addresses. As such, it can temporarily mitigate most issues related to a DNS outage. | ||
| − | ==DNS Flushing== | + | Occasionally, there may be issues with a DNS server caching information that is no longer valid. A DNS Flush will update the information to be valid. If you need to manually flush your DNS on your computer, here's how: |
| − | ===Windows DNS FLush=== | + | |
| + | ===DNS Flushing=== | ||
| + | ====Windows DNS FLush==== | ||
'''Windows Vista/7''' | '''Windows Vista/7''' | ||
Revision as of 12:05, 25 August 2015
Contents
What is DNS?
Overview
DNS (Domain Name System) is a protocol which handles how computers exchange data on the Internet. Simply put, it translates a recognizable name like xmission.com into an IP address like 198.60.22.4. In the background your computer connects to a DNS Server (i.e., Name Server) which manages a database that maps domain names to IP addresses.
When you connect your computer to the Internet, it automatically assigns an IP address that comes from a DHCP server on your network. The job of this DHCP server is to make sure your computer has a IP address and other network configurations it needs to give you access online. Under normal circumstances, XMission connectivity customers will use XMission's DNS. This is handled automatically when you connect. You can refer to this as your Primary DNS.
If you run a business we know that having a reliable connection to the internet is essential since downtime can cause a loss of sales and unhappy customers. In a perfect world we would never have an outage; however outages can and do occur. Therefore, configuring your network for redundancy can be important to mitigate the risk of an outage. DNS resilience is determined by the steps you take to ensure your business, or home network is available to the Internet should your primary DNS service with XMission experience any interruption. Setting up both primary and secondary DNS servers can help keep you online.
Many alternative DNS providers, like OpenDNS and Google's Public DNS, allow you to use their free service as a primary or secondary DNS. Setting them up will take a little configuration on your side but help mitigate issues during an outage: if your primary DNS is unavailable then your secondary name service can be available for redundancy.
Advanced
- What is the Primary DNS Server?
XMissions Primary DNS server is 198.60.22.2. This server is responsible for any new entries and updates from DNS zones. It holds the "Master Copy" of all DNS records.
- What is the Secondary DNS Server?
XMissions Secondary DNS server is 198.60.22.22. This server is mainly for redundancy. It will simulate what is on the Primary DNS server and relatively act the same as our Primary DNS server.
- What are tertiary, quaternary, quinary, senary, septenary, etc. DNS Servers?
These servers are for pure redundancy. You can have many other DNS servers for your connections. Typically these servers are typically offsite, whereas our DNS servers are onsite. If both XMissions Primary and Secondary DNS servers go down, thats when these DNS servers will kick in. Popular providers for this kind of service is OpenDNS and Google's Public DNS.
DNS Caching
Overview
A DNS cache is a local database copy of all domain names translated to IP addresses. As such, it can temporarily mitigate most issues related to a DNS outage.
Occasionally, there may be issues with a DNS server caching information that is no longer valid. A DNS Flush will update the information to be valid. If you need to manually flush your DNS on your computer, here's how:
DNS Flushing
Windows DNS FLush
Windows Vista/7
Click the start button on the bottom left of your screen and navigate to the command prompt (Start > All Programs > Accessories > Command Prompt)
Make sure that you right click on the command prompt application and choose "Run as Administrator"
Type in the command ipconfig /flushdns
Windows 8/8.1
Ensure that you're on the Windows 8 Start Screen.
Simply type cmd and the Windows search bar will appear on the right hand side with search results.
Right click on Command Prompt and click Run as administrator.
Type in the command ipconfig /flushdns
Windows 10
Click the start buttom on the bottom left of your screen, and type in "cmd".
Right click on the command prompt application and choose "Run as Administrator"
type in the command ipconfig /flushdns
Mac OSX DNS Flush
Yosemite
Mac OS X 10.10, you need to do the following:
Open up the command terminal.
Run the command sudo discoveryutil udnsflushcaches
Lion, Mountain Lion, Mavericks
Mac OS X 10.7, 10.8 or 10.9, you need to do the following:
Open up the command terminal.
Run the command sudo killall -HUP mDNSResponder
Snow Leopard
Mac OS X 10.6, you need to do the following:
Open up a command terminal.
Run the command sudo dscacheutil -flushcache
Leopard and below
Mac OS X 10.5.1 or below, you need to do the following:
Open a command terminal.
Run the command sudo lookupd -flushcache
Linux DNS Flush
Open up a command terminal
Run the command sudo /etc/init.d/nscd restart
XMission DNS
XMission provides basic and advanced name service options...
Basic DNS Setup
XMissions DNS: 198.60.22.2, 198.60.22.22. Any XMission connects should automatically obtain these two IP addresses when connecting to the internet, however, if you need assistance adding these to your connection, feel free to contact support. Toll Free: 1-877-964-7746 Local: 801-539-0852
Advanced DNS Configuration Options
While xmission's name service is very reliable we encourage businesses and individuals who prioritize always being online to consider some advanced configuration options including DNS caching and using an additional offsite service like OpenDNS and Googles Public DNS for redundancy.
Other DNS Options
OpenDNS
Probably the oldest that are still around. They offer a variety of free and paid services. Their IP address are 208.67.222.222 and 208.67.220.220
Google Public DNS
You may have see these number or heard of them and didn't know what they were. Well now you know Google Public DNS IP address are 8.8.8.8 and 8.8.4.4
