Everything you need to know about wired networking on the Mac

The end of an Ethernet cable. [Pixabay]

When you think about networking devices together, many people immediately jump to setting up a Wi-Fi network. This is especially true with modern devices in Apple's lineup, as you'll find Wi-Fi connectivity across practically its entire ecosystem.

However, while wireless networking is extremely useful from a setup and usage point of view, there's almost always an opportunity to introduce wired networking into plans. Sometimes it is simply a better idea to string a cable between two points than it is to configure Wi-Fi, and in some cases, may be the best solution.

Not every situation can take advantage of Wi-Fi, with interference affecting reliability and bandwidth limitations potentially becoming a pain point for people who need a solid connection that can handle high-bandwidth transfers.

That's when you turn to wired networking.

Like our guide to Wi-Fi, this article won't explain how to set up a network or fix a problem, but it will go over some of the hardware elements you really should know about before planning to wire your home for your own physical network.

Why use wired networking?

There are a few primary reasons to use wired networking rather than Wi-Fi, and they generally center around reliability, speed, and security.

Firstly, a wired network connection is pretty much as it is described: electrical signals passing packets of data down a wire between computing devices. Cables containing multiple strands of wire are used for electrical signal transfers in both directions.

This simple system has been elaborated on for some time, improving with faster speeds in each major refinement, to a point where most current devices sold with network connections can potentially connect at up to 1 gigabit per second.

There are some types of Wi-Fi connection that can boast faster speeds, with maximum throughputs measurable in multiple gigabits, but typically that only applies under ideal conditions and with many devices communicating to saturate the connection. Under Ethernet networking, that top speed can be achieved by just two devices communicating with each other.

Of course, this is all under optimal conditions, but for wired networking, there's more chance of getting closer to the theoretical speed than Wi-Fi, simply because it is more robust. There's little to go wrong with a physical connection, whereas Wi-Fi can be affected by interference, such as from physical objects blocking line of sight, other radio waves and other transmissions, and even rival Wi-Fi networks.

The reliability and speed therefore makes Wi-Fi a great choice for situations where vast amounts of data need to be transferred regularly, as fast as possible. There can be cases where wired networking is the only answer, such as if there's a 6-foot stone wall separating users from the wireless access point that prevents radio signals from busting through.

There's also the security element to consider. Wi-Fi users have to broadcast encrypted data over radio waves, which can be intercepted by anyone nearby, even by those outside of a building where a Wi-Fi network is in operation.

Sending a signal down a wire could still be intercepted, and it is possible for an attacker to physically connect to a wired network, but there's generally less chance of data being acquired in this way for domestic purposes. The bigger danger will be from an attacker gaining control of a system, which can be done remotely over the Internet, and wouldn't necessarily rely on infiltrating a Wi-FI or wired network directly at all.

Even so, it is usual for Wi-Fi networks to take advantage of wired networking anyway, as wireless access points have to be connected up to a router in the first place, typically by a cable. While mesh networking has reduced the need for a physical connection between wireless access points in recent years, wired network connections are still heavily used for access point deployment in corporate networks.

For home users, the use of wired networking may also be beneficial for their Wi-Fi network. By using wired networking, this reduces the number of devices using Wi-Fi, which can help reduce the strain on the Wi-Fi network and make it run more reliably.

Speeds - Ethernet, Fast Ethernet, Gigabit Ethernet, and 10-Gig Ethernet

There are quite a few names and technologies that are used for wired networking, such as Token Bus networks using coaxial cable or Token ring networks. For the purposes of this article, we're going to be sticking to standards that Apple currently supports in its devices, which is namely Ethernet connections.

Standardized in 1983 as IEEE 802.3, Ethernet has become the dominant networking technology in the world, and has undergone many different refinements over the years. Original versions involved the use of coaxial cable, a common cable type that has been used in many industries to pass signals, such as getting signals from an antenna into a television.

After initial versions that offered speeds of up to 2.94Mbps over a connection, it took a few years for the Institute of Electrical and Electronics Engineers to issue a standard that started to become what we would generally call an Ethernet connection today.

Ethernet - 10 megabits per second, and the start of modern networking

In 1990, IEEE 802.3i standardized a connection type known as 10BASE-T, which enabled transfer speeds of up to 10Mbit, or 1.25 megabytes per second, across the network. The key change for the version was the elimination of coaxial cable and instead the use of "twisted pair" cables.

Rather than using a central core surrounded by an insulated sheathe then an external conductive later and further insulation, twisted pair instead relied on pairs of cables that were actually twisted together along the length of the cable, and with four pairs per physical cable. The twists are what help protect the cables from electromagnetic interference with each other, though it is limited in how much protection it provides.

This cable is known as Category 5 or Cat5, and can be used to carry multiple different types of signal, though is more commonly known for use in networking. In "Power over Ethernet," the cable can even be used to transmit power over a distance to a host device, alongside data.

The standards allow for it to run at up to 100 meters (328 feet) in a single cable length before requiring the use of intermediary hardware, such as a switch or hub, or a repeater to extend for another 100 meters.

The cables are usually terminated at the end with an 8P8C modular plug, though it is more commonly known as an RJ45. This is technically a misnomer as, while it is similar in construction to the same plug used for telephony purposes, it actually lacks a side tab defined by the RJ45S standard that limits where it can be used.

Due to using eight wires in four twisted pairs, there are specific ways of ordering the cables into the plug, with two standard color orders defined by the Telecommunications Industry Association. The ordering, officially known as T568A and T568B, and have to be identically ordered at each end of the cable for it to function normally.

The ordering of the pins are also important as swapping pairs could introduce crosstalk, unwanted and unintended effects on signals of other pairs, which can cause connection errors.

Of course, the discussion of pin order only matters if you're actively creating your own custom-length cables, or installing wall sockets for a cleaner home or office network installation. If you are acquiring ready-made cables, there's no need to worry about the pin order at all.

Most users are extremely unlikely to encounter a network running at 10Mbps unless it is using very old hardware. Still, it is included in this guide as there's a chance you may encounter it, and that it is the precursor to modern-day networking.

Thanks to backward compatibility, newer hardware will still be able to communicate with older items using only this standard, so everything should work fine, albeit quite slowly.

Fast Ethernet - 100 megabits per second

Introduced as part of the IEEE 802.3u standard in 1995 as 100BASE-T, Fast Ethernet is the faster counterpart to Ethernet. As the name suggests, it is faster connection than standard Ethernet, with a maximum bandwidth of 100Mbit.

While there are a few variants, the one generally used for Fast Ethernet is 100BASE-TX, which relies on the use of Cat-5 cabling, though it can also use different versions including Cat5e, Cat6, and Cat7.

The differences in the cabling alter the maximum capabilities of each for networking, including the amount of bandwidth each cable can produce.

In the case of Cat5e, the "enhanced" cable adheres to higher IEEE standards to reduce noise and crosstalk. Like Cat5, Cat5e officially supports a frequency of up to 100MHz, but it is capable of reliably handling higher frequencies of up to 1000Mbps, or 1Gbps.

Again, the use of Cat5 or Cat5e cables allows for network segments to run for up to 100 meters apiece before needing assistance. Given the similarity but improved characteristics, Cat5e has largely replaced Cat5 on the market as the most common type of network cable, and is the most appropriate to use for Fast Ethernet networks, especially given its capability of supporting Gigabit networks.

It is possible to use fiber optic connections as part of a Fast Ethernet network, as well as later generations of network technology, but this is more for enterprise use than for home users.

Just as with Ethernet, the industry is moving onward and upward with network connection speeds, so devices that support Fast Ethernet or 100Mbps connections at maximum are few and far between. Backward compatibility again applies, so newer connection types using Ethernet cables will work with older hardware using Fast Ethernet, but at the slower 100Mbps speed.

Gigabit Ethernet - one gigabit per second

Gigabit Ethernet, which has also been referred to a GbE, 1 GigE, and simply Gigabit, arrived as part of IEEE 802.3ab as 1000BASE-T in 1999. Following how Fast Ethernet added a zero to the bandwidth of Ethernet in its improvement, Gigabit does the same thing, with a maximum theoretical speed of 1Gbps.

As consumers demanded higher speeds and more bandwidth, Gigabit became adopted by device producers, making it probably the most commonly-seen wired network connection you'll find in devices today.

Part of the change in speed increase was due to moving from using two twisted pairs in the cable to all four pairs, maximizing the amount of bandwidth available to use.

While it is possible to use Cat5 and Cat5e cables to handle a gigabit network, its not necessarily the best option. By operating at higher speeds, this makes gigabit networks more susceptible to issues with the cable, including crosstalk, so it may not work at as fast speeds as would be desired at times.

Cat6 cables are made with tighter twists and use a thicker sheathing as well as a nylon spine, further minimizing crosstalk and making them more durable. This makes them extremely useful for gigabit networking as it increases the chance of the connection being as close to ideal as possible.

The increased transmission frequency rate of 250MHz also gives networks more chance of reaching their potential.

However, the physically different cable introduces its own problems, including deploying it in tight spaces with corners and other bends.

While years ago, the cost of the cable would have been a big factor in people continuing to use Cat5e instead of shifting to Cat6 for gigabit-level networks, the general cost is comparable across the board. Now, there's relatively few reasons not to use Cat6 cable in your home installation.

Add in that most of the devices you will be buying will offer gigabit-level speeds or higher in the future, it may be worth future-proofing early.

10 Gig Ethernet - 10 gigabits per second

Also referred to 10GbE and other shortened forms, 10 Gigabit Ethernet is another continuation of the speed progression by shifting the decimal point. As you may suspect, the connection offers theoretical maximum connection speeds of 10Gbps, ten times that of Gigabit, and a thousand times faster than the original Ethernet.

Just as with the others, devices supporting 10 Gigabit Ethernet are also backwards compatible with earlier versions, though they also generally include support for other gigabit-level speeds too, such as 2.5Gbps and 5Gbps.

Given the public's appetite for bandwidth, you would expect it to have been adopted by device producers quite quickly, but given it first appeared in 2002 as part of IEEE 802.ae, it's taken quite a while to get going in comparison to Gigabit Ethernet. Indeed, outside of enterprise usage, there's relatively few devices on the market that actually support 10GbE connections.

That's not to say that it can't be used at home, as it is entirely possible to acquire network cards and adapters to upgrade existing equipment to use the standard, though you can expect to pay a price premium to do so.

For example, you can easily buy an 8-port Gigabit switch from Amazon for under $20 in some cases, as Gigabit Ethernet has matured and vendors are building cheaper consumer-grade hardware for it. Meanwhile searches for 10 Gigabit switches will take you to the higher end of the market intended for commercial use, with prices starting from a few hundred dollars and quickly rising.

Cabling for 10GbE mercifully follows the established pattern of being able to use cables intended for earlier generations. If you shelled out for Cat 6 network cables, you're all set for a move to 10GbE, but you are limited to a maximum distance between segments of 55 meters (180 feet).

A solution to this is to acquire Cat6a cable, which is made to more stringent standards once more, and operates at 500MHz. It also raises the distance limit to 100 meters once again.

Of course, you could always go one stage further.

Cable rated for frequencies of up to 600MHz, called "Category 7" takes advantage of tougher specifications and uses additional shielding throughout the cable to further prevent crosstalk. This enables it to easily support 10GbE at distances of up to 100 meters, as well as having headroom for higher connection speeds.

While support for 10GbE isn't readily available in consumer devices, it is almost certain that the cost of hardware will come down and compatibility will become commonplace as time rolls on.

Cable connections: hubs, switches, routers

While dealing with cables and ensuring the devices you connect to the network meet the standards for the speeds you want, there's another element that you have to consider: infrastructure devices. Hardware like switches, routers, and hubs are needed to connect devices to each other, as well as to expand a network beyond a smaller collection.

However, while the three allow devices to communicate with each other, they do so in slightly different ways.

A hub is the most basic network appliance, as all devices connected to a hub will be able to see each other and communicate over the network. It is also not a smart way to connect devices together, due to how it handles packets of data.

If Computer A sends a packet of data intended for Computer B via a hub, the packet will be sent not only to Computer B, but also every other computer attached to the same switch. There's no intelligent routing, as it simply sends it to all blindly, which can be a problem for networks with high levels of traffic.

A decade ago, hubs were attractive as a really cheap option to get a network running, but as switches became cheaper to buy, hubs fell out of fashion.

A switch can be approximated as an intelligent hub, as it performs practically the same task, but better. As it learns which computers are connected to it, the switch will send a packet of data to its intended recipient, without broadcasting it across the entire network.

This makes switches much better, as it reduces the amount of traffic on the network by simply not broadcasting too many unwanted packets of data.

Routers are, in effect, a switch but with more intelligence. As well as being able to handle traffic flow between computers, it is also able to handle data being sent to and from the network from the Internet and other sources via Network Address Translation.

For example, a computer on the network could send a packet of data to a server online. The router updates the IP address for the sender of the packet from the local IP address of the sender to the IP assigned to the router by the Internet service provider, before sending it onward into the Internet.

When the router gets a packet of data back in response, it is able to apply the intended local recipient computer's IP to the packet, then sends it over the local network to its destination.

Home users will be familiar with the router that their Internet provider offers them, in that it handles not only access to the Internet, but also manages elements of the network as well. For example, it can act as a firewall, as well as handling Dynamic Host Configuration Protocol, DCHP, which doles out IP addresses to computers on the network.

Crossover cables

You technically don't need to use a switch, hub, or router to network two computers together, as it is possible to do so by using a network cable directly between the two. However, you can't simply use a normal network cable (patch cable) to do it.

A crossover cable is a purposefully-mismade network cable that doesn't have the same wire orders on each end of the cable. Specifically, one end uses the T568A ordering while the other is set to T568B, switching over some of the pins in the process.

Given that such a setup limits a network to just two devices, you have no room to expand the network with any ease, unless you replace the cable. In such cases, it's usually a better idea to get two patch cables and a cheap switch instead of going to the trouble of making a crossover cable, as at least it provides the option for expansion.

Wired networking in Apple's ecosystem

Apple's desktop Mac lineup all offer Ethernet connections of some description across the board. There's some variation, but generally you're looking at support for either Gigabit or 10 Gigabit Ethernet.

The 21.5-inch iMac is the only Mac in the group that is equipped with a Gigabit Ethernet port, with no further option to upgrade the built-in option. The Mac mini and 27-inch iMac both have a Gigabit Ethernet port by default, but can be configured to 10 Gigabit for an extra $100.

The iMac Pro ships with one 10 Gigabit connection built-in. The Mac Pro is equipped with a pair of the 10 Gigabit ports, but its plethora of PCIe expansion slots also offer the chance to add more connections if required.

None of the MacBook Pro models have an Ethernet port anymore, but they can be used with hubs and docks that have the connection. Models of iPad Pro with USB-C ports can similarly connect to a wired network using the same sorts of adapters.

The support isn't just limited to USB-C, as there are adapters on the market to connect iPhones and iPads with Lightning ports to Ethernet rather than wireless.

Indeed, at one point, Apple sold its own networking hardware. Its AirPort router line was discontinued in 2018 following years of sale, leaving users to look elsewhere to tend to their networking needs.

Obviously, Apple has made its hardware oriented towards wireless networking. By keeping the ability to use wired networking in place for most of its ecosystem of products, it gives you considerably more connectivity options to explore.

Things to consider

If you are planning an extensive network installation, take the time to plan it out properly. If you're drilling holes and feeding cables through walls, you should consider what network you want, and will need in the future.

For example, it's all well and good to buy a ton of Cat 5e cabling for you to have a functional Gigabit Ethernet network in your home, but that doesn't leave you any headroom for upgrades. If you go for a higher category of cable for your installation, then there's the opportunity to simply change the switch from a Gigabit model to one supporting 10 Gigabit Ethernet down the line when things get cheaper.

Also consider that not all devices on a network will be able to support the connection speeds you desire. You may have some older hardware that may only support Fast Ethernet and not Gigabit, but there may be an upgrade option available to enable that support in some way.

Lastly, bear in mind that you are never going to get to see the maximum network speed. Other hardware on a network, limitations of switches and routers, the length and quality of cables, and other factors can easily drag down the speed away from the theoretical limits.

You can get close, but you're not going to get to the bleeding edge of bandwidth. Get to where you want in terms of speed and settle for that, until the next major jump in connectivity comes along.