[Solved] Gigabit lan but slow internet. ISP verified full bandwidth is present.

[MachineMedic]

Got a weird one here.

I upgraded my internet plan a few weeks ago to a 150Mb/s service. I called in a tech from the ISP to fix a 30~80Mb/s bottleneck that I was seeing. Tech replaced the modem. Tech was then able to achieve 175Mb/s on both his personal and work phones. My phone (on the same network) and my computer (via RJ-45 patch-patch-crossover) are both only able to achieve roughly 80Mb/s and 93Mb/s respectively. I'm willing to write off the low number on my phone as it simply being the crappy phone that it is... but I *know* (and just verified again) that both Ethernet adapters in my computer are capable of gigabit speeds (1,000~1,200Mb/s) between computers using a crossover cable.

This rules out ISP problems, PC hardware, and PC drivers. That only leaves OS & software.

I'm running Windows 10 Home. Kaspersky antivirus. I've tested throughput with my antivirus filter disabled - still 93Mb/s.

Any ideas?

 

[Solaris17]

have you tried a diff speedtest site?

 

[MachineMedic]

Xfinity speed test reads 93Mb/s.
Speedtest.net reads 92.5Mb/s.

 

[Solaris17]

hm. before we dive super deep, I would see if your manufacturer has better/updated ethernet drivers if you havent already.

If thats all set your next best bet is to boot into safe mode (with networking) to make sure kasperskys firewall service isn't interfering since it probably uses a TAP adapter.

 

[Kursah]

I use a mix, speedtest.net is the one I take with the most grains of salt, speedof.me is one I like to rely on for more realistic tests. There's also Google, Charter, etc.

If you connect directly to the modem with your PC via Ethernet cable, do you get higher speed tests?

 

[MachineMedic]

Speedof.me reads 73Mb/s.

Direct connection to the modem is impractical without a 120ft cable. I can relocate my machine temporarily but would prefer save that until after other possibilities have been exhausted. (It's a big heavy S.O.B.) Current connection is cat5e patch from ISP modem to wall, 5e patch within the patch panel (no switch), cat 6 from wall to computer.

Testing safe mode now...

[...]

Speedtest.net in safe mode reads 90Mb/s.

BRB while I take a peek inside the data rings... I want to make sure the wiring inside the wall truly is cat5e.

[...]

All wiring is cat5e except the patch card from 1999. That guy is plain old cat5. Could be the problem. Based on this, moving my computer to attempt a direct cat6 crossover is justified. BRB again...

 

[Solaris17]

check your duplex as well under your ethernet controller properties make sure your at full gig. and not at 100meg

 

[Kursah]

Testing directly at the ISP interface is definitely a diagnostic metric worth looking at IMHO. I'm kind of surprised the ISP didn't suggest trying this already with a laptop or your PC.

I understand it being a pain, if you have another device you could test with that isn't such a pain to move I'd strongly suggest you test this. It'll help narrow down if it's LAN or WAN-side issues. If you connect directly and are testing the same speeds, then it comes down to their lines and services and network load. If you're on a busy section of their hub/zone then that could be it...if its an old line or still has a filter, there could be issues there as well..usually more in the form of packet drops.

If you run continuous pings to something like Google.com, 8.8.8.8, 1.1.1.1, etc. do you notice any dropped packets?

I like to use PingInfoView and PingForLife for these kinds of tests. If you're seeing dropped packets behind your firewall, then I'd also run this test again from a device connected directly to the ISP's modem. If you still see dropped packets, take screenshots, offer to provide them to ISP tech support. Odds are they'll send a tech out to repair "things". Sometimes they'll have to replace lines, terminations, filters, etc. Not sure what kind of ISP service you're running but it's always worth bringing up. Having information like dropped packets before you call the ISP can also negate the concern of having to pay for their on-site services because you've proven their network has issues out of your control and management.

As @Solaris17 said, I'd also check your duplex speed on your system AND your router. Even in your modem, let's verify that your Router-to-Modem isn't in Fast (100Mbps) mode, but is in Gigabit (1000Mbps) mode.

I know in my area an ISP will only promise that their provisioned speeds will be within 80% of what you're paying for, so meaning my 100Mbps connection is testing at 80Mbps, they won't offer to provide support. Yours is substantially lower than that, but hoping we can get you sorted and at least get you within spitting distance of your full speed!

 

[MachineMedic]

Yep. Link speed is only stable at the 100Mb/s setting. Forcing gigabit duplex drops the connection. Moving my PC so I can try direct hookup now...

 

[Solaris17]

I am getting the idea that this wire is piped through your wall? If thats the case your going to want to check the termination point. and then check how your modem connects to this termination point.

 

[OC-Ghost]

Yep. Link speed is only stable at the 100Mb/s setting. Forcing gigabit duplex drops the connection. Moving my PC so I can try direct hookup now...

The crossover cable is the most likely suspect, educated guess its only running over 4pins(max100Mbit). Check/replace cables so its only "normal" cables.

 

[Solaris17]

The crossover cable is the most likely suspect, educated guess its only running over 4pins(max100Mbit). Check/replace cables so its only "normal" cables.

This as well, was going to mention this depending on how you responded when I questioned you on

patch-patch-crossover

All wiring is cat5e except the patch card from 1999.

For normal home users and shit even more advanced networks just use standard cables. The necessity for different cables died when ethernet controllers got smarter. If you have the ability to rebuild your patch panel (if thats what you use) I would be sure to do that.

 

[MachineMedic]

It's the wiring. Direct connection to the modem with my crossover cable ( ) yielded a gigabit connection. Speedtest.net result was 180Mb/s.

I guess from here I'll start with the weakest link and try cutting out the old cat5 patch card from the equation. The weakest link from there should be the cat5e cabling. Failing that, I'll break out the fish tape and see if I can fish in a new cat6 between the two data rings. Failing *even* that, I'll have to try moving the modem. Even if the Ethernet cabling isn't up to snuff, at least the builders were kind enough to drop off a coaxial connection in each room.

Thanks for the help guys!

 

[Solaris17]

glad you solved it! I would rip out that patch card for sure and see if you can correct the main link to whatever distribution method you are using. Should have you upto speed in no time. Otherwise what you can do (if its properly terminated to each room) is check or replace the keystone itself. could just be a bad punch as opposed to an actually physically damaged wire in the wall.

If not and you actually have ethernet ends just sticking out of your wall (please why) cut them off and terminate them to a keystone if you have the skill its mean to avoid situations like this where there could be possible issues with the wire in the wall (by not beating on the wire in the wall itself)

 

[MachineMedic]

That's a really good thought... If removing the patch card doesn't work, maybe I'll ask around and see if I can borrow a cable tester from one of the low voltage guys at work.

 

[eidairaman1]

You mean patch cord, your ISP, was it Coax or DSL/Fiber?

 

[MachineMedic]

Old cat5e branch wiring and cat5 patch panel in the house. Moved the modem upstairs using a different coax branch and connected my computer directly. Full speed at no extra expense... works for me. I can still use the existing wiring to connect peripherals around the house this way, provided they only need 100Mb/s connections. Printers, smart TVs and other silly things that don't need (that much) throughput.