Why can I only get full speed on Linux?

can you show us an example of a oookla speedtest readout (ip masked if it shows?)

Here’s what it looks like on linux. Windows is the exact same except the download speed never goes above 120-130ish. Even stuff like Steam downloads faster on Linux.

Have you tried changing the duplex speed from auto to 1gb?

Yes I forced it to 1gig full duplex

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Windows isn’t helpfully downloading updates in the background?

And then seeding it to the internet, now you have a massive pipe they can abuse?

I checked for updates and there is none available. i also disabled the update share thing. I also only have 30 mbits up so i doubt it will be that helpful.

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Try to turn off Windows Defender and Windows Firewall and see if that makes a difference. If you have any anti-virus software that attempts to perform intrusion detection, that would slow you down drastically.

And leave Jumbo frames off. As a consumer, you will never need it.

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jumbo frames are more trouble than they are worth unless you know ALL your equipment works with them properly and what the max size is for all your gear.

Unless you’re running iSCSI (and even then - benefit isn’t massive) - just turn them off.

I have jumbo frames OFF in an enterprise environment with an all flash array for example (but ON for another filer) because there were some “wierd issues” going on between the array and the end device. Jumbo frames will get you that last 5-10% in a heavily loaded environment; they aren’t going to be any real bigger difference than that to performance. And if you’re dealing with traffic to the internet, you’re just maybe even going to make your router have to work a lot harder to fragment your packets more for re-transmission.

As per @Mastic_Warrior above, i’d check whether or not you are CPU bound (i.e., CPU maxed in task manager) when doing a transfer in windows, and if you are, i’d bet that it is windows defender AV scanning slowing you down (firewall should be OK if it is built-in windows firewall, but anything that does real time anti-malware scanning of network traffic, or writes to disk - or both like defender - will likely slow you down).

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Hmmmmm. I didn’t think to check Windows defender. I’ll look into that. I guess the realtime protection could be eating up a bunch of CPU.

I disabled the Windows firewall and Windows defender and both made no difference. I’m still limited to about 120-130 down on Windows.

Could be shit network driver. Maybe check for updates or a compatible driver direct from the chip vendor.

What network adapter is it?

Realtek 8111F. It’s built into my motherboard. I find it hard to believe that it can’t access the internet at full speed considering I can transfer files between PC’s at full gigabit speed.

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Ok. If it works at gig speed for local traffic then it is something to do with routing.

Is ipv6 perhaps enabled in windows and not in Linux? Could’ve your router shits the bed with ipv6. Or windows is setting up an ipv6 over ipv4 tunnel (teredo I think?) and using that to reach the internet.

I’m not sure. I doubt it’s an issue with the router as it’s brand new and I have no issues under Linux only Windows.

There are a lot of shitty consumer routers out there.

But not necessarily saying it’s your router. Merely that it is routing related. Which means that for some reason there’s a difference between Linux and windows routing in your environment that is OS dependent.

Time to play spot the difference between the IPv4/Ipv6 addresses between the two platforms and whether or not any tunnels are in use.

I do seem to recall that maybe windows sets up an tunnel to access ipv6 internet even if you don’t have native ipv6 (something the typical Linux distro doesn’t do) but maybe my memory is hazy.

That’s the sort of stuff to check though. If it is only non local traffic affected it is related to the way traffic is hitting your router, a tunnel being involved, MTU sizes too big and different fragmentation behaviour as traffic exits your LAN etc.

May also pay to Install wireshark in both OS and see if windows is experiencing a bunch of retransmits or fragment problems etc.

Also. If you have a firewall on your router and it blocks all icmp for ipv6 that can break mtu discovery and other stuff. Which will fuck over windows if it is doing ipv6 and Linux is not for example.

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Hmm. Well I can’t check it right now because I’m busy but later on I’ll check my router firewall settings and see if I can find anything fishy. By default the firewall on my router was disabled so I enabled it on medium protection but I guess it’s possible that it’s causing issues. I’ve never experienced this before so I’m kind of at a loss as to why this only happens on Windows.

I’ll reiterate though. The big give away is that it only impacts non local traffic. For local traffic routing is not involved.

Ipv6, blocked icmp6 and other potential routing related issues (that only impact windows due to configuration differences with the way you have Linux configured) are where you will find the problem.

It is the ISP’s hardware… Can always yell at them. Just leave out the part about Linux working fine.

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Yea it’s ISP hardware. I might do that if I can’t figure it out.

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Otherwise you’re getting close to wireshark time which can be somewhat daunting.

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