Free and Useful Tools for DNS and Network Troubleshooting
When troubleshooting network or DNS problems related to your website, server or other online services, free and useful tools can help you reduce your troubleshooting time.I'll go through five categories of functionality, covering tools that let you:
- Perform DNS lookups
- Perform tests on DNS settings (DNS health)
- Get information about an IP address
- Test network connectivity
- View status of networks on the Internet
Below are the best tools and they're all free. DNS LOOKUPS
Tools in this category allow you to perform DNS lookups, usually on specific DNS records. Even though you can do these things from your own computer with Dig and Nslookup, it can often be helpful to perform DNS lookups from different locations to verify consistent DNS behavior and settings.List of Tools:
DNSstuff, Serversniff.net, AjaxUtils.com, IPtools.com, DNSgoodies.com, How is my DNS?, Ajax DNS, MyDNStools.info. DNS HEALTH TESTS
These tests will look at the DNS settings for a domain name and its authoritative DNS servers. They'll flag anything they consider a problem or potential problem. They can be very useful if you are having DNS-related problems that are hard to track down.List of Tools:
IntoDNS, Serversniff.net, How is my DNS?, CheckDNS.net. IP INFORMATION
Sometimes, it can be useful to get more information about an IP address. For example, to see where it's hosted. The most common tool here is: IP WHOIS, which is similar to a domain WHOIS but with information regarding who owns an IP address (often an ISP or data center).List of Tools:
Serversniff.net, DNSstuff, AjaxUtils.com, IPtools.com, DNSgoodies.com, Ajax DNS, MyDNStools.info. NETWORK TESTS
Basic network connectivity tests can be useful to do from different locations to help you narrow down a problem. For that reason, it’s effective to have access to several different services that can perform ping and traceroutes (we can assume they all use different servers).List of Tools:
DNSstuff, Serversniff.net, AjaxUtils.com, IPtools.com, DNSgoodies.com, Pingdom Tools, Ajax DNS, MyDNStools.info. NETWORK STATUS
Some sites provide continuously updated reports on the status of networks and servers. Here are two that you might find fruitful. Since what they provide is a bit different, we've given them a brief explanation. You can also read more further down in this article.List of Tools:
Internet Health Report (connectivity status between different ISPs), Netcraft (uptime for a number of different websites and hosting providers). MORE ABOUT THE TOOLS
Here's an expanded explanation about the tools included in this article. The best you can do, though, is to check them out yourself, play around with them, and bookmark the ones you wish to keep handy if you end up needing them.
- Internet Health Report – This report from Keynote shows the status of peering connections between different ISPs and can be a good way to find out if there are general connectivity issues for a certain ISP.
- Netcraft – Provides (among other things) an uptime report where you can look at the availability of a number of different websites and hosting providers.
- Serversniff.net – Provides a very large number of tools related to networking, DNS and domain names.
- DNSstuff – Probably the most well-known set of tools in this article. Has a wide variety of DNS, domain name and network-related tools. Also has a DNS health test, but that isn’t free.
- IPtools.com – Similar in approach to DNSstuff, with a large set of tools related to DNS, domain names and networking.
- DNSgoodies.com – Basic DNS and network tools.
- How is my DNS? – As the name suggests, this tool focuses on DNS lookups and also has a DNS health test.
- CheckDNS.net – Another dedicated DNS health test.
- Pingdom Tools – A visual ping and traceroute tool from us here at Pingdom. Also includes a website load test.
- Ajax DNS – A set of network and DNS tools.
- MyDNStools.info – Provides a relatively large number of tools related to DNS and networking.
- IntoDNS – A dedicated DNS health test with a good overview of the results.
The tools included range from the basic to the advanced. I wanted to give you a wide range of services to pick from and experiment with. Tastes differ: while some prefer as much visual output as possible, others will prefer raw text output just as if they were sitting by a terminal.Don't hesitate to perform tests from more than one service (and from more than one location). Having to several similar tools is a good thing.I hope you found this article useful. If you feel I have missed a really good (free) network or DNS tool, please post it inthe comments.