Adding Probes to North America and Europe along with an IP Change [BR]

NodePing continues to grow!
We’re adding two new probes in the North America region one to the Europe region.

Las Vegas, Nevada (US) – NV (
Seattle, Washington (US) – WA (
Madrid, Spain (ES) – ES (

In addition, we have one IP change to our current probe in Brazil:
BR will change from to

These changes will take place 2014-07-02. Please update your firewalls appropriately.

As always, a current list of all the IP addresses for our probe servers can be found in the FAQ.

[UPDATE – 2014-07-02 09:48GMT-6] – New probes are online and IP change for BR complete

rDNS: Monitoring the Flip Side of DNS

DNS monitoring is an important part of keeping your services available. DNS is what allows your browser to turn the name ‘’ into the IP address Without proper functioning DNS, your website, email, and other services would be unreachable.

One often neglected part of DNS monitoring is the rDNS, or reverse DNS, entries. As the name suggests, rDNS is the reverse of DNS. It maps an IP address to a hostname using a special PTR DNS record type. In essence, it associates an IP address to a specific hostname or domain.

PTR records are used by all kinds of utilities and services like the humble ‘ping’ and ‘traceroute’ as well as more complex FCrDNS-enabled services. A forward-confirmed reverse DNS (FCrDNS) verification uses the PTR record to associate a domain owner with an IP address. It’s not a rock-solid form of validating ownership but is usually considered enough to be used for whitelisting servers for SMTP services because spammers usually can’t fake an rDNS record when they forge domains.

If you’re sending email from a server, you should have a proper PTR record in place that includes the domain for the ‘from’ address. This will help ensure your email from that server will not get sent to the spam bucket. A PTR, or ‘pointer’, record is usually configured by whomever owns the IP address so you often have to put in a ticket with your colocation or service provider to set or change rDNS entries.

NodePing is one of very few server monitoring services that can monitor rDNS entries. To set up a rDNS check, select ‘DNS’ from the check type and ‘PTR’ from the record type dropdown. It’s important to note that your PTR record will be in what is commonly called ‘arpa’ format. An example of the ‘arpa’ format for the IP is ‘’ – please note how the octets are in reverse order, not the numbers. Set the ‘arpa’ address for your IP address in the ‘Query’ text field. You’ll also want to set the ‘Expected Response:’ field to the hostname for that IP, example: ‘’.

For more information about rDNS/PTR monitoring or our DNS check capabilities in general, check out our DNS check documentation.

NodePing site update

We updated the web application that provides the front end to our website and server monitoring service today. Most of the changes to the site are incremental improvements. Most notably, we’ve been working on our billing system to make it more flexible and support tiered billing.

At the same time, we have made a minor adjustment to our Terms of Service. Ironically, the change to our Terms of Service is about changes to the Terms of Service. In light of some recent news stories about other companies, we wanted to make it clear that our ToS can change, but that changes impact you when you have actual notice of the change. We don’t have any intention of sneaking in changes that materially alter what you agreed to when you signed up without giving you notice and a chance to decide if you wish to continue to use the service.

We will continue to work on improving and extending our service. NodePing is already an outstanding monitoring service and an excellent value. We are committed to providing the best monitoring service for the best price. We think we are already doing that, and we plan to make it continually better yet.

Your feedback, as always, is welcome both here in the comments, on our Contact page, or in email to