Difference between revisions of "DNS Resolution Issues"
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# '''Authoritative''' — These servers are authorities for the names they are designated responsible for, typically these servers are never addressed directly and instead a resolver issues a referral to them. | # '''Authoritative''' — These servers are authorities for the names they are designated responsible for, typically these servers are never addressed directly and instead a resolver issues a referral to them. | ||
| − | == | + | ==Causes== |
Often times people have ongoing issues with DNS resolution, this is often the result of overloaded servers, bad DNS resolvers and so forth. Among these issues: | Often times people have ongoing issues with DNS resolution, this is often the result of overloaded servers, bad DNS resolvers and so forth. Among these issues: | ||
| − | ===Router DNS=== | + | ===Overloaded/underpowered Router DNS=== |
Many home routers implement their own DNS forwarders, meaning they have mini DNS resolution servers onboard that all computers use instead of external servers directly. Often times what can happen is the caches on these instances can be corrupted or they can cause the router to run out of memory causing both DNS and non-DNS traffic to lag. | Many home routers implement their own DNS forwarders, meaning they have mini DNS resolution servers onboard that all computers use instead of external servers directly. Often times what can happen is the caches on these instances can be corrupted or they can cause the router to run out of memory causing both DNS and non-DNS traffic to lag. | ||
| − | ===ISP DNS=== | + | ===Overloaded/underpowered ISP DNS=== |
Often times ISPs offer DNS resolution as a value-add service that's not guarenteed nor as protected by contracts as the actual connectivity. This means often times their DNS resolvers may be underequipped to handle peak load by many customers at once. | Often times ISPs offer DNS resolution as a value-add service that's not guarenteed nor as protected by contracts as the actual connectivity. This means often times their DNS resolvers may be underequipped to handle peak load by many customers at once. | ||
| − | === | + | ===DNS resolution provider tampering with responses=== |
| − | It is not advised to use OpenDNS as their implementation violates the DNS standard, they claim the options can be switched off or modified by using a control panel on their website but it is still a violation as DNS is meant to be an authoritative lookup system, not a filtration or advertising platform. | + | It is not advised to use providers like OpenDNS as their implementation violates the DNS standard, they claim the options can be switched off or modified by using a control panel on their website but it is still a violation as DNS is meant to be an authoritative lookup system, not a filtration or advertising platform. |
==Fixing the problem== | ==Fixing the problem== | ||
Latest revision as of 17:41, 17 January 2014
Contents
Preface
DNS is the Domain Name System, it is a hierarchical system in which names (digibase.ca) get translated to IP addresses (72.38.129.202). DNS has two classes of servers:
- Resolvers — These servers are what users use to access the DNS to look up names, typically these are assigned by ISPs in many cases automatically.
- Authoritative — These servers are authorities for the names they are designated responsible for, typically these servers are never addressed directly and instead a resolver issues a referral to them.
Causes
Often times people have ongoing issues with DNS resolution, this is often the result of overloaded servers, bad DNS resolvers and so forth. Among these issues:
Overloaded/underpowered Router DNS
Many home routers implement their own DNS forwarders, meaning they have mini DNS resolution servers onboard that all computers use instead of external servers directly. Often times what can happen is the caches on these instances can be corrupted or they can cause the router to run out of memory causing both DNS and non-DNS traffic to lag.
Overloaded/underpowered ISP DNS
Often times ISPs offer DNS resolution as a value-add service that's not guarenteed nor as protected by contracts as the actual connectivity. This means often times their DNS resolvers may be underequipped to handle peak load by many customers at once.
DNS resolution provider tampering with responses
It is not advised to use providers like OpenDNS as their implementation violates the DNS standard, they claim the options can be switched off or modified by using a control panel on their website but it is still a violation as DNS is meant to be an authoritative lookup system, not a filtration or advertising platform.
Fixing the problem
Often times the issues can be resolved by utilizing a known good DNS server set that are stable and faster than utilzing the default provided DNS servers:
Windows: This can be done by going into your Network Adapter Settings (found via the control panel or Network and Sharing Center), right clicking the adapter and going into properties, then selecting IPv4 and properties again, then set manual DNS servers (but leaving automatic IP selection alone)
Linux: This can be set via /etc/resolv.conf or your distro's method of setting this, KDE distros with full graphical network management can do this by bringing up "Edit Connections" on the Network Manager and going into the IPv4 tab and setting up "Other DNS servers"
Servers to use
Servers we recommend (choose any 2 of these, mixing operators is acceptable):
Level3
- 4.2.2.2
- 4.2.2.3
- 4.2.2.4
- 4.2.2.5
- 4.2.2.6
Digibase
- 72.38.129.202
- 8.8.8.8
- 8.8.4.4
