Dns troubleshooting
From Webpipe Wiki
When troubleshooting DNS problems, there are several good tools that can give you information about your domain.
dnsreport.com
The best site to check for a detailed description of your domain's DNS record is www.dnsreport.com. It grades each detail on a Pass/Warn/Fail and will give you a good idea of any problems that your DNS records may have.
Using nslookup
If you use Windows, then you can use the 'nslookup' command line tool to troubleshoot some DNS problems.
1- Exit to a command prompt (Start => Run => type in "cmd" => click OK)
2- type "nslookup" at the command prompt to begin using nslookup. By default it will connect to the DNS server specified in your IP address settings (or that was given to you by DHCP if you have DHCP enabled). For home users with a router, this may be the IP Address of your router (usually 192.168.0.1). Webpipe ISP customers should be set to 205.244.47.6 and 205.244.47.8.
3- At nslookup's '>' prompt, simply type the name of the record you would like to look up.
C:\> nslookup
Default Server: dnscache1.webpipe.net
Address 205.244.47.6
> webpipe.net
Server: dnscache1.webpipe.net
Address: 205.244.47.6
Non-authoritative answer:
Name: webpipe.net
Address 63.172.126.209
4- To change the DNS server that you are connected to, simply type server <SERVER_NAME>. You can then look up DNS records from that server. It may be handy to query the authoritative name server for your domain to make sure that it's giving out correct information. Webpipe Hosting customers' name servers are ns1.webpipe.net and ns2.webpipe.net
C:\> nslookup
Default Server: dnscache1.webpipe.net
Address 205.244.47.6
> server ns1.webpipe.net
Default Server: ns1.webpipe.net
Address: 205.244.47.4
> webpipe.net
Server: ns1.webpipe.net
Address: 205.244.47.4
Name: webpipe.net
Address: 63.172.126.209
5- You can also use other remote DNS servers. Try your ISP's and any other open DNS servers that you know of. DNS Server cache the records that they receive, so if you find a DNS server that is incorrect, it may be several hours, or even days until the incorrect record is updated. Make sure that your authoritative Name Server (the ones specified in your whois record) are correct and that the SOA Serial Number has been updated.
6- To query an MX record (or any other type of record) type set type=mx
7- When you are all done, type exit to quit nslookup, then exit again to close the DOS box.
Clearing your DNS Cache
If you are using a Windows Computer then Windows cache's DNS entries and you may need to delete an entry out of the cache. To clear your Windows DNS Cache, do the following:
1- Click Start => Run
2- Type cmd in the box, then click OK
3- At the DOS prompt, type in ipconfig /flushdns to clear your computer's DNS Cache.
