Question Why are my speeds capped at 100Mbps when going through wired ethernet in house ?

[sam2k51]

Hello,

I've recently moved into a new house (built in 2018) which has built in ethernet ports throughout the house. They were annoying not labelled but I've now figured out what port near my router relates to what port in other rooms.

I've recently tried plugging my game console in through the port in the lounge and then from the related port by my router and then into the router. I should be getting speeds of around 500Mbps (and I do get this when I test via WiFi) but the console only gets 100.

I've tested quite a few things, like plugging directly into the router and my speeds go up to 500, tested both cables also checked the ports themselves and they are both wired up as T568B and also checked all of the other ports in the house and they are only getting 100Mbps as well and I can't figure out why I'm getting a low speed.

Does anyone have any ideas what's causing it to be slow? Also please bear with me I'm new to a lot of this and I'm still learning!

 

[kanewolf]

Hello,

I've recently moved into a new house (built in 2018) which has built in ethernet ports throughout the house. They were annoying not labelled but I've now figured out what port near my router relates to what port in other rooms.

I've recently tried plugging my game console in through the port in the lounge and then from the related port by my router and then into the router. I should be getting speeds of around 500Mbps (and I do get this when I test via WiFi) but the console only gets 100.

I've tested quite a few things, like plugging directly into the router and my speeds go up to 500, tested both cables also checked the ports themselves and they are both wired up as T568B and also checked all of the other ports in the house and they are only getting 100Mbps as well and I can't figure out why I'm getting a low speed.

Does anyone have any ideas what's causing it to be slow? Also please bear with me I'm new to a lot of this and I'm still learning!

There are a few possible reasons. But bad terminations on the in-wall wiring is #1. Then the obvious error of using an old 100Mbit ethernet switch rather than a gigabit. Third possibility is you have a laptop which only has 100Mbit hardware. Fourth you have damage to one of the eight wires in your ethernet port.

 

[USAFRet]

Capped at ~100mbps is almost certainly cable related.

 

[chillhouse1]

try uncap ethernet speed, open device manager, then properties-advanced of network adapter, then select Speed and Duplex from the Property column, and expand the Value dropdown

 

[sam2k51]

There are a few possible reasons. But bad terminations on the in-wall wiring is #1. Then the obvious error of using an old 100Mbit ethernet switch rather than a gigabit. Third possibility is you have a laptop which only has 100Mbit hardware. Fourth you have damage to one of the eight wires in your ethernet port.

Thank you for the help! Do you think it would be worth rewiring 2 of the ports to see if that makes a difference?

Also I'm not sure if there is a switch or if it is just straight A to B, I've had a look around my house by I can find any sort of switch anywhere, is there any way to find out?

I don't think it is the laptop as I have used it wired before in other places and got much faster speeds!

 

[dev_cyberpunk]

Does anyone have any ideas what's causing it to be slow? Also please bear with me I'm new to a lot of this and I'm still learning!

bad cabling or router.
disconnect all of the lan ports but 1 and go to that end and speed test it. Also, find out what connection link speed its running by looking at the status of the ethernet interface in the network properties window.

If you have a damaged and shorted cable, the instant you plug it in, the problem will return.

Otherwise there are other things that can be wrong. like too long of runs, kinks in the wire, or they used the wrong type and the heat deteriorated the cables.

 

[LordVile]

bad cabling or router.
disconnect all of the lan ports but 1 and go to that end and speed test it. Also, find out what connection link speed its running by looking at the status of the ethernet interface in the network properties window.

If you have a damaged and shorted cable, the instant you plug it in, the problem will return.

Otherwise there are other things that can be wrong. like too long of runs, kinks in the wire, or they used the wrong type and the heat deteriorated the cables.

Just sounds like they used Cat5 cable

 

[dev_cyberpunk]

Just sounds like they used Cat5 cable

plenum grade in residential walls and attic degrade, plus if runs have twists and kinks in the wire its done. The speeds they reported seemed to come from an internet speed test than the actual link speed.
I installed my own networks, one 10Gb and 1Gb about 15 years ago. Both were cat 6 CMX wire and never had issues. Since CAT 8 CMX bulk is cheaper now, I'm going to be adding that and use the spare cat 6 for distributed audio.

 

[LordVile]

plenum grade in residential walls and attic degrade, plus if runs have twists and kinks in the wire its done. The speeds they reported seemed to come from an internet speed test than the actual link speed.
I installed my own networks, one 10Gb and 1Gb about 15 years ago. Both were cat 6 CMX wire and never had issues. Since CAT 8 CMX bulk is cheaper now, I'm going to be adding that and use the spare cat 6 for distributed audio.

Generally if it degrades tough you'll have more issues than just a drop in speed and being limited to exactly the Cat5 cap is a little too neat for me.

 

[sam2k51]

Just sounds like they used Cat5 cable

It looks like they used Cat5e, at least that's what the ports say (I suppose they could've have used Cat5 cable still though).

plenum grade in residential walls and attic degrade, plus if runs have twists and kinks in the wire its done. The speeds they reported seemed to come from an internet speed test than the actual link speed.
I installed my own networks, one 10Gb and 1Gb about 15 years ago. Both were cat 6 CMX wire and never had issues. Since CAT 8 CMX bulk is cheaper now, I'm going to be adding that and use the spare cat 6 for distributed audio.

I'm getting the speeds from speed tests and also my router shows me what the max speed is for each cable device when plugged in. Anything going through the ports in the wall say max 100Mbps. (When plugging directly into the router it goes up to 1Gb)

 

[sam2k51]

Generally if it degrades tough you'll have more issues than just a drop in speed and being limited to exactly the Cat5 cap is a little too neat for me.

I have asked around a couple of places and people seem to think that there might be a hidden switch or panel, but looking around the house I can't seem to find anything!

 

[bill001g]

I like this device because it will let you locate wires as well as test ethernet wiring. There are many other units I just happen to have a link to this one.

https://www.amazon.com/dp/B07TMDFG3W

These cheap unit though will not find stuff like if you have the wrong color wires on the wrong pins. The that units can detect when the pairs are split and stuff are extremely expensive.

You are best off looking at the wiring and see if it follows pattern 568a or 568b.

Ethernet cables are point to point. If there is a switch the cables likely go to some central location. You can run a device like this to first find both ends of cable. You plug the sender into some jack and then take the probe and listen for a tone when you touch other cables. This unit is not good enough to trace wires in the walls but for more money those devices do exist.

After you find both ends and you think the wires colors and pattern look correct you can test if the port really works and all 8 pins can send signals end to end.

In general when a port runs at only 100mbps there is a issue with either the blue or brown pair...assuming 568a/b wiring patterns. You used to see ports wired with only 4 wires rather than all 8 that also causes it to only run at 100mbps.