DEV Community: techslang

Public and Private IP Addresses: A Beginner’s Guide

techslang — Mon, 13 Sep 2021 14:03:46 +0000

By now, you probably know what an IP address is but for those who are truly new to the subject, it is simply a set of numbers that identifies a device (computer, mobile device, or IoT device) on the Internet. In this guide, let’s talk about the different types of IP addresses, how they differ from one another, and dive into public and private IP addresses and how they work.

IP Address Types

Before we get started with public and private addresses, we need to understand the types of IP addresses. Classifying IP addresses can be done in three ways.

IPv4 or IPv6

IPv4 addresses are more widely used than IPv6 addresses today. In fact, 94% of Internet-connected devices are identified by IPv4 addresses. IPv4 uses a 32-bit address scheme to store more than 4 billion addresses. It is made up of four sets of numeric characters, ranging from 1 to 255, separated by periods. An example would be 127.255.255.255.

As more devices accessed the Web, experts began worrying about running out of available IPv4 addresses, and so entered IPv6.

An IPv6 address comprises eight sets of alphanumeric characters (with four characters per set), separated by colons, such as 2001:0db8:85a3:0000:0000:8a2e:0370:7334. And because of its 128-bit address space, users now have an additional 340 undecillion IPv6 addresses to use. You can take a closer look at the IPv6 address allocations at this Internet Assigned Numbers Authority (IANA) page or learn about their distribution across countries compared to IPv4 addresses by using a list of IP addresses by country.

Static or Dynamic

A static IP address does not change, a dynamic address does. When a device with a static IP address accesses the Internet, its identifier never changes. Most devices, though, use dynamic IP addresses that are assigned by their ISPs. These can change periodically, depending on which IP address (from the ones the ISP owns) is not in use at a given time. Static and dynamic IP addresses can fall under either the IPv4 or IPv6 address space.

Note, however, that you can’t control which of the IP address types mentioned above get assigned to your network. Users’ IP addresses are determined by availability.

Public and Private

IP addresses, whether IPv4 or IPv6 and static or dynamic, can also be categorized as either public or private. Simply put, a public IP address is one which anyone on the Internet can see while a private IP address is only accessible to users who are connected to the same network (either home or corporate). Read on to find out more about how they work in the next section.

How Public and Private IP Addresses Work

Public IP addresses are directly accessible over the Internet. Your ISP assigns them to your network routers. Each time you visit a website, this public IP address gets picked up by the site owner’s network log. Think of it as a post office box number that you wouldn’t mind giving out to almost anyone as opposed to letting them know your home address. Similarly, public IP addresses don’t tell network owners as much about your location and personal details, as their records would point to your ISP.

Private IP addresses, on the other hand, are those that your network router assigns to each of your devices. Each private address is unique so your connected devices can talk to each other (and not get confused) within the network. When router-connected devices access the Internet, their private IP addresses won’t be visible to others. What website owners will see is your public or router’s IP address.

The following diagram shows how they differ from each other:

Public and Private IP Address Ranges

Not all IP addresses are publicly seen on the Internet. The IP ranges reserved for private use are:

-10.0.0.0–10.255.255.255
-172.16.0.0–172.31.255.255
-192.168.0.0–192.168.255.255

All other IP addresses excluded from the ranges above are public IP addresses.

To recap, no one sees private IP addresses on the Internet. They don’t get recorded in network logs. Network owners only see your public IP address when you visit their websites, purchase something on their e-commerce platforms, or download files from their sites.

Why Knowing Public and Private IP Addresses Matters

At the end of the day, any home or corporate router is identifiable by its public IP address. If your business goal is to determine where your traffic comes from, then you need to pay attention to your site visitors’ public IP addresses. It doesn’t matter if it's an IPv4 or IPv6 address or if it’s a static or dynamic IP address. Given their public IP address and armed with a list of IP addresses by country or an IP geolocation database, you can already identify where they are based.

If you’re a network administrator for a company or complex home network, you also need to pay attention to all connected devices’ private IP addresses. Each system must have a unique private IP address. Your printer should not share the same private IP address as your Voice over Internet Protocol (VoIP) phone. If they do and you want to print a document from your laptop, your computer may not be able to correctly identify the printer from the phone and you’d fail at accomplishing that task.

In this article, you’ve learned about public and private IP addresses and their difference from other types. To reiterate, whether you use a static or dynamic IPv4 or IPv6 address, anyone with access to a list of IP addresses by country or an IP geolocation database can track the traffic coming from your network via your public IP address. And if you want to maintain the security of your home network and your privacy, you may want to ensure that only your public IP address is visible to everyone.

How to Keep Track of Newly Registered Domains for Brand Protection

techslang — Wed, 01 Sep 2021 11:50:14 +0000

Brand protection covers a wide range of activities that prevent other entities from using a brand name and intellectual property. Digitalization has further increased the scope of brand protection to include preserving one’s domain brand reputation. With this improvement, developers and security specialists could be asked to implement various domain brand protection measures, which cover monitoring newly registered domains.

In this post, we answer questions relevant to domain brand protection and monitoring newly registered domains. We also tackle how API integration works compared to using newly registered domains data feed.

What Is Domain Brand Reputation?

Domain brand reputation refers to how your brand name is used in the domain name space, which ultimately affects your overall brand reputation. For example, if your brand name repeatedly appears in a list of phishing domains, your reputation and business can suffer. Multiple studies, such as those of Comparitech and ArcServe, have established that consumers and investors tend to walk away from companies that have been involved in a cyber attack.

And since most cyber attacks start with phishing, it’s vital to ensure that your brand name is not used in this or any other malicious campaigns. Why is that so? Threat actors often register domains that contain the names of legitimate companies to make their campaigns more believable. Here’s a recent example. Between 1 July and 3 August 2021 thousands of cybersquatting domains that contain the names of the top 10 impersonated brands were registered, and about 32% of these domains have been reported “malicious.”

Aside from being used in cyber attacks, trademark infringers and counterfeiters also use domain names. These actors bank on a brand’s reputation and legitimacy to lure consumers into buying cheaper but lower-quality products.

Monitoring Newly Registered Domains

Newly registered domains are among the weapons threat actors use in their attacks. Hence, monitoring domain name registrations could be an integral part of a company’s overall brand protection strategy. It can be done in several ways, including integrating an API that monitors domain registrations or using a newly registered domains data feed. We describe both options below.

Brand Monitor API

The brand monitor API we tested for this post monitors all newly registered and deleted domains that contain a selected brand name. To illustrate, let’s say you want to keep track of newly registered domains containing the word “google.” The API returned 1,437 domains added and dropped within the past 21 days.

This particular API can be integrated using client libraries in Python or other languages. And since all API calls rely on the provider’s existing infrastructure, there's no need to set up or maintain your own database. Of course, functionality may vary depending on a provider, but overall using a brand monitor API wouldn’t demand too much from your company’s resources. Businesses looking for cost-effective solutions can therefore choose to integrate it into their brand protection strategies.

Newly Registered Domains Data Feed

Another way to monitor newly registered domains is by subscribing to and downloading data feeds via HTTPS or FTP. As with any database integration, you would need to analyze the data in your local environment before integrating it into your backend systems. The goal of the data processing is to extract brand-related domain names.

Additionally, you would need to regularly download the most updated data feed to ensure accuracy.

Here’s an example of the newly registered domains data feed we mentioned earlier for the .com TLD space for 29 August 2021, which contains 96,619 domains. Eleven of them contain the word “google.”

While this monitoring method takes time and more human resources, analyzing the data shouldn’t be too tricky since these databases come in comma-separated values (CSV) format.

Using newly registered domains data feed might be more suitable for entities with strict firewall rules and those that can’t communicate through API calls, such as governmental entities, for instance.

If you’re developing brand protection solutions, incorporating newly registered domain monitoring functionality could make your product more inclusive. The additional functionality allows your product to detect potential typosquatting or cybersquatting domains. These domain names can turn out to have been registered by trademark infringers or, worse, cybercriminals.

7 Best Email Verification APIs to Choose From

techslang — Fri, 23 Jul 2021 11:21:01 +0000

Some may say that email marketing is the way to go. For developers, that means creating products that can help organizations boost their marketing performance. One way to do that is by producing an email verification API their fellow developers can implement in their respective companies while keeping these latest stats in mind:

The worldwide email user base in 2019 was 3.9 billion, which is slated to reach 4.5 billion by 2024.
A 2019 Campaign Monitor study of 1,000 small business owners ranked email marketing as the second most effective means to build brand awareness. Email marketing, in fact, had the highest return on investment (ROI) for small businesses.

An effective email verification API should help users clean up their distribution lists to avoid high bounce rates. Why? Because high bounce rates could land their domains on spam blocklists, which could affect their reputation and, consequently, bottom line significantly. For the companies’ development team, that translates to failure as well.

One way to keep invalid email addresses (i.e., those that lead to hard bounces) out of distribution lists is by employing an email verification API. But that’s not all email validation is good for. It’s also useful for ramping up cybersecurity, keeping freemium abusers out of product pages, and avoiding spam traps, which are a few of the goals developers are hired for as well.

What Is an Email Verification API Good For?

Email verification APIs validate if an email address exists and can receive messages through various checks. Using them can help companies enjoy several benefits. But creating your own email verification API can take months. Pooling the data required to build a database and updating it daily isn’t easy. Instead of building one from scratch, you can opt to integrate a reliable API into your existing systems and solutions instead to get the advantages cited below.

Help Keep Your Organization’s Bounce Rate to a Minimum

You probably know that the higher a company’s bounce rate is, the lower its email-sending reputability is. In fact, your email-sending reputation has a lot to do with how effective your marketing efforts are. The lower your bounce rate, the more likely your intended recipients are to receive and read your emails. The opposite, however, is bound to land your domain on a spam blocklist. That means none of your customers, current and potential, may never even have a chance to see your emails in their inboxes.

An effective email verification API uses email-sending simulation techniques to ensure the validity of an address. It checks if it has all the necessary components (e.g., a corresponding inbox, a mail exchanger [MX] server and records, the proper format, etc.) to receive messages. All these checks help ensure your marketing messages get to their intended destinations.

Help Your Organization Keep Catch-All Email Addresses Out

A catch-all email address is designed to catch all messages for a number of users. Some of these users may no longer be part of the company. Others rarely, if at all, check the catch-all inbox much less read or respond to emails sent to it.

Sending emails to a catch-all email address could translate to a high bounce rate and so on and so forth. You can avoid this cycle by using an email verification API that flags catch-all email addresses on the fly.

Help Your Organization Keep Potential Freemium Abusers and Fraudsters Out

While not everyone who uses an invalid or temporary email address is a freemium abuser or cybercriminal, some could be. A potential scenario could be that the user mistyped his or her email address while signing up for an account. And disposable email address users could just be protecting their privacy.

An email verification API can lessen the likelihood that your distribution list contains addresses that could potentially belong to free trial abusers who use disposable addresses to sign up multiple times so they can keep using your product without ever having to pay. It can also keep threat actors who use temporary email addresses containing legitimate brand names out of your network. An example would be microsoft@[disposable domain].[TLD]. This address could trick you into thinking you’re communicating with a user from Microsoft when you’re actually not.

What Do You Need to Consider When Choosing an Email Verification API?

An effective email verification API should run various checks to validate an email address. These tests include the following:

Format check: All valid email addresses follow this format:

Local-part (owner’s or department name) + @ + domain name (company or email service provider’s name)

An invalid email address doesn’t follow this format and will get the following result from an email verification API format check:

formatCheck: String
"false"

Simple Mail Transfer Protocol (SMTP) check: All valid email addresses should have connected mailboxes to receive messages. An invalid email address that doesn’t have one will get this result from an email verification API’s SMTP check:

smtpCheck: String
"false"

Domain Name System (DNS) and MX record check: All valid email addresses should have existing domains or a working MX server to receive messages. An invalid email address will get this result from an email verification API’s DNS and MX record check:

dnsCheck: String
"false"

mxRecords: Array
0: 
1:
2:

Free check: Just like legitimate users, threat actors can also get email addresses from free email services like Gmail, Yahoo, and many others. If you want to keep them out of your subscription list, watch out for email addresses that get this result from an email verification API’s free check:

freeCheck: String
"true"

Disposable check: Many freemium abusers use temporary email addresses so they can sign up for free trials multiple times thereby being able to use products without paying for them ever. Be wary of email addresses then that get this result from an email verification API’s disposable check:

disposableCheck: String
"true"

Catch-all check: Messages sent to catch-all addresses rarely or never get opened. Watch out for email addresses then that give this result for an email verification API’s catch-all check:

catchAllCheck: String
"true"

Most email verification APIs give results in JavaScript Object Notation (JSON) or eXtensible Markup Language (XML) format. But some provide more readable and shareable reports via custom URLs that when clicked opens the report specifically for the email address queried.

What Email Verification APIs Should Be on Your Selection List?

We compared seven email verification APIs based on the six tests we believe an effective tool should perform to validate email addresses so you can spend less time and effort looking for the right fit for your company.

Email Verification API

Email Verification API performs comprehensive checks on email addresses that website visitors use for registration. As such, it helps reduce email bounces, block spam, and more. It ensures that an email address follows the correct format and has a working SMTP connection and an MX server. It also alerts users if the email address is a free, disposable, and/or catch-all address.

Users can enjoy the tool’s benefits for as little as US$18 for 10,000 queries a month.

Results come in JSON format or a more readable report with a shareable custom link.

emailAddress: String
"support@whoisxmlapi.com"
formatCheck: String
"true"
smtpCheck: String
"true"
dnsCheck: String
"true"
freeCheck: String
"false"
disposableCheck: String
"false"
catchAllCheck: String
"true"
mxRecords: Array
0: 
"alt1.aspmx.l.google.com."
,
1: 
"aspmx2.googlemail.com."
,
2: 
"aspmx.l.google.com."
,
3: 
"aspmx3.googlemail.com."
,
4: 
"alt2.aspmx.l.google.com."
,
audit: Object
auditCreatedDate: 
"2021-07-21 01:01:48.000 UTC"
,
auditUpdatedDate: 
"2021-07-21 01:01:48.000 UTC"

QuickEmailVerification

QuickEmailVerification performs five of the six email validation checks mentioned earlier. It prevents email addresses with the incorrect format and without an SMTP connection from ending up in your distribution list. It flags free, disposable, and catch-all email addresses, too.

Using the tool costs US$420 monthly and allows for 15,000 queries a day. However, more plans are available as well.

It gives results in JSON format.

Mailgun

Mailgun targets developers who want to integrate email validation into their products. It performs two of the six tests to validate email addresses—format and free checks.

Users can harness the tool’s power by paying a minimum of US$35 for 50,000 queries a month.

It gives results in JSON format.

Email Verifier API

Email Verifier API checks if an email address follows the required format, ensures that it isn’t from a free service provider, and determines if it is a disposable and/or catch-all address.

Users can use the tool for a one-time payment of US$70 for 10,000 queries.

Results come in JSON and XML formats.

Trumail

Trumail performs four checks—format, free, disposable, and catch-all—on a given email address and provides JSON, JSONP, and XML results.

Users can enjoy the benefits the tool provides at US$69 for 10,000 queries.

{
    "address": "support@whoisxmlapi.com",
    "username": "support",
    "domain": "whoisxmlapi.com",
    "md5Hash": "02364a441d5b4021790e20e84c214131",
    "suggestion": "",
    "validFormat": true,
    "deliverable": true,
    "fullInbox": false,
    "hostExists": true,
    "catchAll": true,
    "gravatar": false,
    "role": true,
    "disposable": false,
    "free": false
}

SendGrid

SendGrid checks if an email address meets required formatting specifications, if it has a corresponding MX server and DNS records, and if it was created via a free email service.

Users can make 10,000 basic queries for US$14.95 a month.

Results come in JSON format.

Email Validator

Email Validator performs all six checks—format, SMTP, DNS and MX, free, disposable, and catch-all—on a given email address, providing results in JSON format.

Querying 10,000 email addresses costs US$59 a month.

Given the ideal list of checks an email verification API is expected to perform, we hope you find the right fit for your requirements from among the choices listed in this post.