Are the terms IP and IPv4 interchangeable

Website monitoring

Internet Protocol version 4 (IPv4) is the fourth version of the standard that directs Internet traffic and other packet-switched networks. It was introduced in 1982 by the Internet Engineering Task Force (IETF). Despite the restriction of a 32-bit address format, IPv4 is the most widespread version of the protocol. With a little less than 4.3 billion unique addresses, the availability of addresses was quickly exhausted. Refined ingenuity, however, extended the life of the protocol and the pool of available addresses persisted through 2011.

What is an IP address?

An Internet Protocol address is a unique identifier for devices connected to a network. Using this unique identifier, devices can find each other and communicate with each other. Initially, the main types of devices that needed an IP address were network devices such as computers, servers, routers, and printers. However, with the Internet of Things, the list expands to include cell phones, televisions, refrigerators, light bulbs, and other things capable of receiving and exchanging information over a network.

Understand IPv4 addresses

An IPv4 address is a series of four 8-bit binary numbers separated by a decimal point. Although a unique 32-bit number can be represented using any numbering system, most IP addresses are shown in dotted decimal notation.

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Early IPv4 routing

The standard originally defined the first octet as the network identifier, but with only 256 unique values, the number of available networks quickly dried up. Over the years, several different changes have extended the life of IPv4. First, the available addresses were divided into five classes: A, B, C, D and E.

The class system determined which class a network belonged to based on the first octet.

  • The network class A octet begins with 0. The first octet identifies the network. Class A supports 127 networks, each with 16 million hosts.
  • The network class B octet begins with 10. The first and second octets identify the network. Class B supports 16,000 networks, each with 65,000 hosts.
  • The network class C octet begins with 110. The first three octets identify the network. Class C supports 2 million networks, each with 254 hosts.
  • The network class D octet begins with 1110. Class D is reserved for multicast groups.
  • The network class E octet begins with 1111. Class E is reserved for future use.

Each class uses a different number of bits to identify the network, and thus affects how many networks and hosts can be in a class. For example: The first three octets of class C describe the network, while the fourth octet describes the host on the network. The IETF later replaced the class system, also known as "classful", with subnet masks that made it possible to distribute addresses to each address-bit boundary.

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IPv4 today

In 1993, the introduction of Classless Inter-Domain Routing (CIDR) enabled greater flexibility in the allocation of address blocks. CIDR adds a suffix to the IP address to determine how many of the leading bits represent the network address. For IPv4, this is a number between 0 and 32. The higher the suffix, the fewer available host addresses there are on the network.

CIDR slowed the growth of routing tables and extended the life of IPv4 by reducing the number of wasted addresses that plagued the class system. CIDR is still the most widely used network routing method for IPv4 and IPv6 routing today.

IPv4 address exhaustion

The last distribution of IPv4 address blocks to the five regional internet registries took place in 2011, one of which had run out within two months. The individual Internet service providers maintain the IPv4 standard by recycling addresses as soon as they become available again.

As already mentioned, the upper limit of IPv4 is just under 4.3 billion addresses. With the explosive growth of the Internet and the Internet of Things, the number of addresses available was quickly exhausted. As a solution to this situation, the IETF published the IPv6 standard with the 128-bit address format and an almost inexhaustible 340 sextillion (340 followed by 37 zeros) available addresses. Learn more about IPv4 addresses.

IPv4 and IPv6 compatibility

Although IPv4 and IPv6 use CIDR to determine network and host addresses, the two protocols are not interchangeable. IPv6 also fixes many other network problems that exist with IPv4, such as smaller routing tables, simplified packet headers, and the use of multicast rather than broadcast connections.

A single device can support both IPv4 and IPv6. The use of dual-stack IP enables a single router, switch or server to process both address protocols. You cannot connect to a device that only uses IPv6 over an IPv4 connection, and vice versa.

IPv4 and loading time

A load that IPv4 carries with the expansion of the number of addresses affects the network speed. In the perfect IPv6 environment, IPv6 outperforms IPv4. But the IPv6 network still requires work, so IPv4 is often faster, depending on the local architecture. An algorithm called Happy Eyeballs, used by some browsers, checks the speed of both network protocols and uses the faster one.

DNS for IPv4 and IPv6

The Domain Name System (DNS) supports both protocols. The DNS stores the IP addresses of one or both protocols and responds to every request to resolve the domain name with both IP addresses (a website can have multiple addresses for both protocols).

The DNS stores IPv4 addresses in the A record. The DNS stores IPv6 addresses in the AAAA record. The client can then decide which protocol to use. "

Monitoring your IPv4 addresses

The IP address is a vulnerable element of the network protocol. If a hacker gets access to the DNS settings, he can change the IP address. This allows it to direct visitors to a malicious website or simply prevent them from viewing your page. To protect you against hacking, DNS monitoring can check the IP address once a minute. DNS monitoring can also check and verify other records that are contained in your DNS records, such as the MX and NS records.

Monitor both IPv4 and IPv6

Just because both protocols route to the same server doesn't mean both protocols will work properly. Explicitly monitoring IPv6 and IPv4 is possible with uptime monitoring (for websites and web services). Select the protocol in the test object settings and define the monitoring checkpoints. For IPv6, set checkpoints that only support IPv6 natively, or use all of them with an IPv6 simulation on IPv4.

Which protocol does my website support?

Use the free DNS tool and enter a domain name, for example Click on Start Test.

The free DNS tool resolves the address. That is, the tool sends a request to the DNS and receives your DNS records. Search the result for the A and AAAA records. You can have several of the two, or just one or the other.

  • If the result contains an A record, the website supports IPv4 (most websites support IPv4).
  • If the result contains an AAAA record, the website supports IPv6 (less often).
  • If the result contains both records, the website supports both protocols.

The most important points

  • IPv4 is the most widely used Internet routing protocol (compared to IPv6).
  • IPv6 solves the problem of exhausted IPv4 addresses.
  • IPv4 uses a 32-bit address system.
  • IPv6 and IPv4 can exist on the same device if dual stack is enabled.
  • Happy Eyeballs is an algorithm that allows a device or browser to choose the faster protocol from a target.
  • IPv6 will eventually replace IPv4 and the use of IPv6 is growing 5% annually.
  • One website or service can be reachable through a protocol, but report an error for the other. Monitor both IPv6 and IPv4 addresses for availability.

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