避免 DNS 中断:通过 DNS 监视减少停机时间

访问您的网站的访问者能够在合理的时间内访问所需的内容,这一点非常重要。 DNS 监视是确保一致性能和连接性的第一步。

Cloudflare, Amazon, Microsoft, and Google are some of the largest managed Domain Name Server (DNS) service providers in the world. They are also just a few of the many DNS providers that have struggled with DNS outages. In fact, Cloudflare had an outage earlier this year due to a bad software deployment.

Whether your websites are hosted with one of the above-mentioned providers, or within your own network, your website availability is only as strong as the weakest link, and your DNS records are the first links in that chain. In fact, whenever somebody new attempts to reach your website, they do not only hop from their computer to your DNS server directly to your website, but they may make a dozen hops across the Internet before they land on your website.

 

Common DNS Outages

Even with the proper setup of DNS records on a network of highly available servers, a website can be vulnerable to a number of common outages, including the following:

  • High TTL (Time to Live)
  • DNS amplification attacks
  • DNS poisoning/spoofing
  • DDoS attacks
  • Hardware/network failures

Percentage of outage time can be determined by downtime calculation formulas. In response to outages like these, organizations will attempt to tighten up the setup of their DNS records by switching providers, implementing DNS whitelists, limiting the number of requests allowed, and limiting the hosts allowed to make a request.

While such changes in response to service outages are generally a good thing, there are often unintended consequences to such changes. For example, when switching providers, there can be a delay while the TTL runs out, too many or too few IP addresses are ported over, or something else along the chain of communication gets lost between server administrators, ISPs, DNS hosts, and network or firewall administrators.

 

DNS Monitoring: Decrease Downtime and Ensure Consistent Connectivity

It’s extremely important that visitors to your site are able to reach the content they want, and within a reasonable amount of time. DNS monitoring is the first step in ensuring consistent performance and connectivity.

  • Verify DNS resolution
  • Web and mail server availability
  • Proxy server availability
  • Diagnose recurring DNS issues
  • Immediate Alerts when issues occur

Not only will our DNS monitoring solution help you identify and alert you of any of the common DNS outages, utilizing our global network of monitoring hosts will help you to identify when any changes you make accidentally limits connectivity to your websites from around the world. Our platform supports the following commonly used DNS record types:

  • A(IPV4 host address record)
  • AAAA(IPv6 host address record)
  • CNAME(Canonical name for alias record)
  • MX(Mail exchange record)
  • NS(Name server record)
  • PTR(Points to a canonical record)
  • SOA(Start of authority record)
  • SPF(Sender Policy Framework legacy record)
  • TXT(Text record for general information)

Learn more about DNS monitoring within the Dotcom-Monitor suite or sign up for a 30-day free trial.

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