What Is an IP Address? Functions, Types, and Versions

Every location in the world has a unique address. This address helps you find and reach any place you want to visit. Similarly, we navigate the digital world with multiple devices connected through the internet. But how do we locate a specific device in this vast digital landscape?

The answer lies in IP addresses. Every device connected to the internet has a unique IP address. This IP address functions like a digital address, allowing other devices to locate and communicate with yours over the internet.

This guide will explore everything you need to know about IP addresses, including their different types and how they influence your email marketing efforts. We'll also share tips to improve your IP reputation.

What is an IP address?

An IP address (Internet Protocol address) is a string of numbers separated by periods or colons that identifies each device connected to a network.

You’ve probably seen IP addresses that look something like this: 192.168.1.1 or this: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. These addresses ensure that data sent over the Internet gets to the right place.

An IP address has two main parts:

1. Network ID: This comprises the first three sets of address numbers. For example, in 192.168.1.1, the network ID is 192.168.1. It indicates which network the device is on.

2. Host ID: This is the fourth number in the address. In the same example, the host ID is the final number, 1. It refers to the specific device on that network. Usually, your router is assigned .1, and each subsequent device gets assigned .2, .3, and so on.

Functions of an IP address

IP addresses perform two main functions essential for data transmission over the internet.

1. Host/network interface identification

An IP address identifies the device or network interface. It is like a unique name or ID distinguishing your device from others on the network. This ensures that the data you send and receive goes to the correct device.

2. Location addressing

When you send data online, your device uses its IP address to direct the data to its intended destination, defined by another IP address. The data is then divided into packets containing the destination IP address, ensuring they all reach the correct location.

An IP address helps specify where your device is located within the network and where the packets need to be delivered.

Types of IP addresses

IP addresses are designed to fulfill different roles, facilitating efficient and effective communication between devices. Let’s explore each type, how they differ, and their common use cases.

Public and private IP addresses

Public IP addresses are like your home address. They let devices on the internet find and communicate with your device. Private IP addresses are like room numbers in your house. They help devices within your network talk to each other without exposure to the internet.

The differences between the two are given in the table below:

Aspect	Public IP address	Private IP address
Visibility	Visible on the internet	Visible only within the local network
Uniqueness	Unique across the internet	Unique only within the local network
Use case	Connecting to websites and online services	Connecting to other devices within a home or office network
Example	203.0.113.1	192.168.1.1

Static and dynamic IP addresses

Static IP addresses are IP addresses that don’t change. They are great for services that need a consistent address, like web servers. Dynamic IP addresses, on the other hand, change regularly. This is ideal for everyday tasks like browsing the web.

The differences between them are outlined in the table below:

Aspect	Static IP address	Dynamic IP address
Change	Remains constant	Changes periodically
Assignment	Manually assigned	Automatically assigned by the network
Use case	Hosting websites, running servers	Regular internet browsing, connecting home devices
Example	198.51.100.1	Varies (e.g., 192.168.0.1 today, 192.168.0.2 tomorrow)

Dedicated IP and shared IP

A dedicated IP address is a unique IP address assigned exclusively to a single user or organization, providing full control and reliability. This is particularly beneficial for business websites and email marketing. In contrast, multiple users or organizations use a shared IP address, making it a cost-effective option for personal websites but with potential limitations in control and performance.

The differences between them are listed in the table below:

Aspect	Dedicated IP address	Shared IP address
Ownership	Assigned to one user or organization	Shared among multiple users
Control	Full control over the IP address	Limited control due to shared usage
Use case	Running a business website, email marketing	Shared hosting for personal websites

See what an Email Marketing Specialist says about the benefits of using a dedicated IP address.

IP address versions

The Internet uses two main versions of IP addresses: IPv4 and IPv6. These versions are essential to ensure that every device connected to the Internet has a unique identifier. Initially, IPv4 was sufficient for the relatively small number of devices. However, as the Internet grew and more devices came online, the need for a more expansive addressing system became apparent, leading to the development of IPv6. Let’s read about each one in detail.

IPv4 addresses

IPv4 addresses are the most common and are formatted as four groups of numbers separated by periods, such as 192.168.1.1. Each group can be up to three digits long, making the whole address up to 15 characters. This system has been used for many years but needs more unique addresses due to the growing number of devices.

IPv6 addresses

IPv6 addresses are designed to solve the IP address shortage problem. They are formatted as eight groups of letters and numbers separated by colons, such as 2001:0db8:85a3:0000:0000:8a2e:0370:7334, and can be up to 39 characters long. This format provides many possible unique addresses, accommodating all internet-connected devices' current and future needs.

The table below highlights the key differences between IPv4 and IPv6.

Feature	IPv4	IPv6
Format	Numeric (e.g., 192.168.1.1)	Alphanumeric (e.g., 2001:0db8:85a3::8a2e:0370:7334)
Length	Up to 15 characters	Up to 39 characters
Address space	Approximately 4.3 billion addresses	Approximately 340 undecillion addresses
Configuration	Manual or DHCP	Automatic (Stateless Address Autoconfiguration)

How IP addresses are used in email marketing

Every email is sent through an IP address. Internet service providers (ISPs) assign a score to a sender's IP based on factors like the quality of the emails, frequency of emails sent, and recipients' interactions. This score is known as the sender's email reputation or IP reputation.

Your IP address's reputation influences email clients' decisions on delivering your message to subscribers' inboxes. Therefore, as an email marketer, ensuring your IP address has a good reputation for better email deliverability is crucial.

If your IP reputation is consistently bad, you may even be added to blacklists. These lists consist of suspicious and malicious IP addresses. If any emails are sent through these, they’re instantly blocked by the email clients. On the contrary, emailing from a trusted IP address is more likely to reach the recipient's inbox.

Several factors can influence the effectiveness and reputation of an IP address, especially in the context of email marketing. Here are some key factors that may affect your IP reputation:

1. Using a shared IP address: Sharing an IP with others can hurt your reputation if others on the shared IP address send spammy emails.

2. Spike in volume of emails: Sending too many emails too quickly from a new IP address can trigger spam filters. The solution to this is warming up your IP address, which means gradually increasing the number of emails you send.

3. Engaging in spam practices: Sending unsolicited emails or using misleading subject lines can negatively impact your IP reputation and even get your IP blacklisted.

4. Poor email list management: Sending emails to invalid addresses increases bounce rates and harms your reputation. Prevent this by managing your email lists better.

5. Lack of authentication: SPF, DKIM, and DMARC authentication are necessary for your emails to be seen as trustworthy and safe.

6. High complaint rate: If many recipients mark your emails as spam, your IP reputation will suffer. This is why you must always send relevant and engaging content.

Conclusion

Understanding IP addresses is crucial for effective email marketing and overall internet functionality. An IP address acts like a digital signature for your emails, influencing deliverability and reputation. Regularly monitoring your IP address, following the best practices, and choosing reputable service providers can maintain a good IP reputation and ensure your emails reach your audience's inbox. Whether using a shared or dedicated IP, staying informed and proactive is key to successful email marketing efforts.

An easy and quick way of getting yourself to follow the right practices to maintain your IP reputation is to use a reputed ESP like Mailmodo. Mailmodo ensures authentication of emails and helps you improve your deliverability by keeping track of your email lists, segmenting them, personalizing your emails, and helping you create engaging emails. Check out the full set of features it offers, or try it for free now.