Google Webmaster Tools reported crawl errors due to DNS, server connectivity, and robots.txt unavailable

Question

I am experiencing the following site errors on Google Webmaster Tools.

1. DNS: couldn’t communicate with the DNS server.
2. Server connectivity: request timed out or site is blocking Google.
3. Robots.txt fetch: Googlebot wasn't able to access your robots.txt file and postponed crawling your site rather than risk crawling disallowed pages.

How can I resolve this?

UPDATE

did a nslookup. Below are the results with non-authoritative answer. Is there any issue given non-authoritative answer? (Note actual domain name is replaced with xxx here for privacy)

Server: 127.0.0.1

Address: 127.0.0.1#53

Non-authoritative answer: www.xxx.com canonical name = xxx.com.

Name: xxx.com

Ping is reachable but takes an awful high round trip time.

Site does come up in browser, no issue.

So is this a case of oddities or should I bring this to my registrar's attention or host?

Answer 1

It sounds like your registrar and/or host had some downtime. If your registrar is not your host, then I would be the registrar DNS failed to respond to requests. This is one of the reasons why I always recommend high quality registrars and hosts though this can happen for other reasons too such as network error along the route. It is possible that neither your registrar or host is at fault.

There is no way to know for sure. It would be helpful if Google could provide some basic information so these problems can be diagnosed. I suggest using one of the online monitoring tools for a while to see if you have issues to worry about. It is possible this was just an anomaly and nothing for you to fix.

What you can do right now is... use the Google Webmaster Tools to Fetch as Google your home page. This will tell you if you have a continuing issue that needs to be addressed.

If it fails, you can do a nslookup example.com to see if your domain name is resolving to an IP address. If this fails, contact your registrar. You can also ping your domain name or IP address to see if it reachable. If this fails, contact your host. As well, you can always use your browser to see if your site comes up. If all of this works, then I would not worry about the message. We all can get these oddities from time to time though rare.