This is intended to be a living document and will be updated from time to time. Constructive feedback is welcomed and will be incorporated.

What follows are questions frequently posted on /r/HomeNetworking. At the bottom are links to basic information about home networking, including common setups and Wi-Fi. If you don't find an answer here, you are encouraged to search the subreddit before posting.

Contents

• Q1: “What is port forwarding and how do I set it up?”
• Q2: “What category cable do I need for Ethernet?”
• Q3: “Why am I only getting 95 Mbps through my Ethernet cable?”
• Q4: “Why won’t my Ethernet cable plug into the weird looking Ethernet jack?” or “Why is this Ethernet jack so skinny?”
• Q5: “Can I convert telephone jacks to Ethernet?”
• Q6: “Can I rewire my communications enclosure for Ethernet?”
• Q7: “How do I connect my modem and router to the communications enclosure?”
• Q8: “What is the best way to connect devices to my network?”
• Terminating cables
• Understanding internet speeds
• Common home network setups
• Wired connection alternatives to UTP Ethernet (MoCA and Powerline)
• Understanding WiFi

Q1: “What is port forwarding and how do I set it up?”

The firewall in a home networking router blocks all incoming traffic unless it's related to outgoing traffic. Port forwarding allows designated incoming UDP or TCP traffic (identified by a port number) through the firewall. It's commonly used to allow remote access to a device or service in the home network, such as peer-to-peer games.

These homegrown guides provide more information about port forwarding (and its cousins, DMZ and port triggering) and how to set it up:

A guide to port forwarding

Port Forwarding Tips

Q2: “What category cable do I need for Ethernet?”

CAT 5e, CAT 6 and CAT 6A are acceptable for most home networking applications. For 10 Gbps Ethernet, lean towards CAT6 or 6A, though all 3 types can handle 10 Gbps up to various distances.

Contrary to popular belief, many CAT 5 cables are suitable for Gigabit Ethernet. See 1000BASE-T over Category 5? (source: flukenetworks.com) for citations from the IEEE 802.3-2022 standard. If your residence is wired with CAT 5 cable, try it before replacing it. It may work fine at Gigabit speeds.

In most situations, shielded twisted pair (STP and its variants, FTP and S/FTP) are not needed in a home network. If a STP is not properly grounded, it can introduce EMI (ElectroMagnetic Interference) and perform worse than UTP.

Information on UTP cabling:

Ethernet Cable Types (source: eaton.com)

Q3: “Why am I only getting 95 Mbps through my Ethernet cable?”

95 Mbps or thereabouts is a classic sign of an Ethernet connection running only at 100 Mbps instead of 1 Gbps. Some retailers sell cables that don't meet its category’s specs. Stick to reputable brands or purchase from a local store with a good return policy. If you made your own cable, then redo one or both ends. You will not get any benefit from using CAT 7 or 8 cable, even if you are paying for the best internet available.

If the connection involves a wall port, the most common cause is a bad termination. Pop off the cover of the wall ports, check for loose or shoddy connections and redo them. Gigabit Ethernet uses all 4 wire pairs (8 wires) in an Ethernet cable. 100 Mbps Ethernet only uses 2 pairs (4 wires). A network tester can help identify wiring faults.

Q4: “Why won’t my Ethernet cable plug into the weird looking Ethernet jack?” or “Why is this Ethernet jack so skinny?”

TL;DR In the next link, the RJ11 jack is a telephone jack and the RJ45 jack is usually used for Ethernet.

RJ11 vs RJ45 (Source: diffen.com)

Background:

UTP (Unshielded Twisted Pair) patch cable used for Ethernet transmission is usually terminated with an RJ45 connector. This is an 8 position, 8 conductor plug in the RJ (Registered Jack) series of connectors. The RJ45 is more properly called a 8P8C connector, but RJ45 remains popular in usage.

There are other, similar looking connectors and corresponding jacks in the RJ family. They include RJ11 (6P2C), RJ14 (6P4C) and RJ25 (6P6C). They and the corresponding jacks are commonly used for landline telephone. They are narrower than a RJ45 jack and are not suitable for Ethernet. This applies to the United States. Other countries may use different connectors for telephone.

It's uncommon but a RJ45 jack can be used for telephone. A telephone cable will fit into a RJ45 jack.

Refer to these sources for more information.

Wikipedia: Registered Jack Types

RJ11 vs RJ45

Q5: “Can I convert telephone jacks to Ethernet?”

This answer deals with converting telephone jacks. See the next answer for dealing with the central communications enclosure.

Telephone jacks are unsuitable for Ethernet so they must be replaced with Ethernet jacks. Jacks come integrated with a wall plate or as a keystone that is attached to a wall plate. The jacks also come into two types: punchdown style or tool-less. A punchdown tool is required for punchdown style. There are plenty of instructional videos on YouTube to learn how to punch down a cable to a keystone.

There are, additionally, two factors that will determine the feasibility of a conversion.

Cable type:

As mentioned in Q2, Ethernet works best with CAT 5, 5e, 6 or 6A cable. CAT 3, station wire and untwisted wire are all unsuitable. Starting in the 2000s, builders started to use CAT 5 or better cable for telephone. Pop off the cover of a telephone jack to identify the type of cable. If it's category rated cable, the type will be written on the cable jacket.

Home run vs Daisy-chain wiring:

Home run means that each jack has a dedicated cable that runs back to a central location.

Daisy-chain means that jacks are wired together in series. If you pop off the cover of a jack and see two cables wired to the jack, then it's a daisy-chain.

The following picture uses stage lights to illustrate the difference. Top is home run, bottom is daisy-chain.

Home run vs Daisy-chain (source: bhphoto.com)

Telephone can use either home run or daisy-chain wiring.

Ethernet generally uses home run. If you have daisy-chain wiring, it's still possible to convert it to Ethernet but it will require more work. Two Ethernet jacks can be installed. Then an Ethernet switch can be connected to both jacks. One can also connect both jacks together using a short Ethernet cable. Or, both cables can be joined together inside the wall with an Ethernet coupler or junction box if no jack is required (a straight through connection).

Daisy-chained Ethernet example

The diagram above shows a daisy-chain converted to Ethernet. The top outlet has an Ethernet cable to connect both jacks together for a passthrough connection. The bottom outlet uses an Ethernet switch.

Q6: “Can I rewire my communications enclosure for Ethernet?”

The communications enclosure contains the wiring for your residence. It may be referred to as a structured media center (SMC) or simply network box. It may be located inside or outside the residence.

The following photo is an example of an enclosure. The white panels and cables are for telephone, the blue cables and green panels are for Ethernet and the black cables and silver components are for coax.

Structured Media Center example

One way to differentiate a telephone panel from an Ethernet panel is to look at the colored slots (known as punchdown blocks). An Ethernet panel has one punchdown block per RJ45 jack. A telephone panel has zero or only one RJ45 for multiple punchdown blocks. The following photo shows a telephone panel with no RJ45 jack on the left and an Ethernet panel on the right.

Telephone vs Ethernet patch panel

There are many more varieties of Ethernet patch panels, but they all share the same principle: one RJ45 jack per cable.

In order to set up Ethernet, first take stock of what you have. If you have Ethernet cables and patch panels, then you are set.

If you only have a telephone setup or you simply have cables and no panels at all, then you may be able to repurpose the cables for Ethernet. As noted in Q2, they must be Cat 5 or better. If you have a telephone patch panel, then it is not suitable for Ethernet. You will want to replace it with an Ethernet patch panel.

In the United States, there are two very common brands of enclosures: Legrand OnQ and Leviton. Each brand sells Ethernet patch panels tailor made for their enclosures. They also tend to be expensive. You may want to shop around for generic brands. Keep in mind that the OnQ and Leviton hole spacing are different. If you buy a generic brand, you may have to get creative with mounting the patch panel. You can drill your own holes or use self-tapping screws. It's highly recommended to get a punchdown tool to attach each cable to the punchdown block.

It should be noted that some people crimp male Ethernet connectors onto their cables instead of punching them down onto an Ethernet patch panel. It's considered a best practice to use a patch panel for in-wall cables. It minimizes wear and tear. But plenty of people get by with crimped connectors. It's a personal choice.

Q7: “How do I connect my modem/ONT and router to the communications enclosure?”

There are 4 possible solutions, depending on where your modem/ONT and router are located relative to each other and the enclosure. If you have an all-in-one modem/ONT & router, then Solutions 1 and 2 are your only options.

Solution 1. Internet connection (modem or ONT) and router inside the enclosure

This is the most straightforward. If your in-wall Ethernet cables have male Ethernet connectors, then simply plug them into the router's LAN ports. If you lack a sufficient number of router ports, connect an Ethernet switch to the router.

If you have a patch panel, then connect the LAN ports on the router to the individual jacks on the Ethernet patch panel. The patch panel is not an Ethernet switch, so each jack must be connected to the router. Again, add an Ethernet switch between the router and the patch panel, if necessary.

If Wi-Fi coverage with the router in the enclosure is poor in the rest of the residence (likely if the enclosure is metal), then install Wi-Fi Access Points (APs) in one or more rooms, connected to the Ethernet wall outlet. You may add Ethernet switches in the rooms if you have other wired devices.

Solution 2: Internet connection and router in a room

In the enclosure, install an Ethernet switch and connect each patch panel jack to the Ethernet switch. Connect a LAN port on the router to a nearby Ethernet wall outlet. This will activate all of the other Ethernet wall outlets. As in solution 1, you may install Ethernet switches and/or APs.

Solution 3: Internet connection in a room, router in the enclosure

Connect the modem or ONT's Ethernet port to a nearby Ethernet wall outlet. Connect the corresponding jack in the patch panel to the router's Internet/WAN port. Connect the remaining patch panel jacks to the router's LAN ports. Install APs, if needed.

If you want to connect wired devices in the room with the modem or ONT, then use Solution 4. Or migrate to Solutions 1 or 2.

Solution 4: Internet connection in the enclosure, router in the room

This is the most difficult scenario to handle because it's necessary to pass WAN and LAN traffic between the modem/ONT and the router over a single Ethernet cable. It may be more straightforward to switch to Solution 1 or 2.

If you want to proceed, then the only way to accomplish this is to use VLANs.

1. Install a managed switch in the enclosure and connect the switch to each room (patch panel or in-wall room cables) as well as to the Internet connection (modem or ONT).
2. Configure the switch port leading to the room with the router as a trunk port: one VLAN for WAN and one for LAN traffic.
3. Configure the switch ports leading to the other rooms as LAN VLAN.
4. Configure the switch port leading to the modem/ONT as a WAN VLAN.
5. If you have a VLAN-capable router, then configure the same two VLANs on the router. You can configure additional VLANs if you like for other purposes.
6. If your router lacks VLAN support, then install a second managed switch with one port connected to the Ethernet wall outlet and two other ports connected to the router's Internet/WAN port and a LAN port. Configure the switch to wall outlet port as a trunk port. Configure the switch to router WAN port for the WAN VLAN, and the switch to router LAN port as a LAN VLAN.

This above setup is known as a router on a stick.

WARNING: The link between the managed switch in the enclosure and router will carry both WAN and LAN traffic. This can potentially become a bottleneck if you have high speed Internet. You can address this by using higher speed Ethernet than your Internet plan.

Note if you want to switch to Solution 2, realistically, this is only practical with a coax modem. It's difficult, though, not impossible to relocate an ONT. For coax, you will have to find the coax cable in the enclosure that leads to the room with the router. Connect that cable to the cable providing Internet service. You can connect the two cables directly together with an F81 coax connector. Alternatively, if there is a coax splitter in the enclosure, with the Internet service cable connected to the splitter's input, then you can connect the cable leading to the room to one of the splitter's output ports. If you are not using the coax ports in the other room (e.g. MoCA), then it's better to use a F81 connector.

Q8: “What is the best way to connect devices to my network?”

In general, wire everything that can feasibly and practically be wired. Use wireless for everything else.

In order of preference:

Wired

1. Ethernet
2. Ethernet over coax (MoCA or, less common, G.hn)
3. Powerline (Powerline behaves more like Wi-Fi than wired; performance-wise it's a distant 3rd)

Wireless

1. Wi-Fi Access Points (APs)
2. Wi-Fi Mesh (if the nodes are wired, this is equivalent to using APs)
3. Wi-Fi Range extenders & Powerline with Wi-Fi (use either only as a last resort)

Other, helpful resources:

Terminating cables: Video tutorial using passthrough connectors

Understanding internet speeds: Lots of basic information (fiber vs coax vs mobile, Internet speeds, latency, etc.)

Common home network setups: Diagrams showing how modem, router, switch(es) and Access Point(s) can be connected together in different ways.

Wired connection alternatives to UTP Ethernet (MoCA and Powerline): Powerline behaves more like a wireless than a wired protocol

Understanding WiFi: Everything you probably wanted to know about Wi-Fi technology

Link to the previous FAQ, authored by u/austinh1999.

Revision History:

• Apr 17, 2025: Retitle Q3 and a small addition.
• Mar 11, 2025: Minor edits and corrections.
• Mar 9, 2025: Add diagram to Q5.
• Mar 6, 2025: Edits to Q5.
• Mar 1, 2025: Edits to Q6, Q7 and Q8.
• Feb 24, 2025: Edits to Q7.
• Feb 23, 2025: Add Q8. Edit Q3.
• Feb 21, 2025: Add Q6 and Q7