2.5GBe USB LAN

Guide + info. First it was neccesary to add another (working) source for packages:

deb [trusted=yes] http://archive.debian.org/debian-security jessie/updates main non-free contrib

So i could download and install classic: sudo, nano, make, usbutils, latestkeyring, freexiankeyring, kernelplus, then i added linux-image-extra just for sure, and surprisingly also dkms, build-essentials, and linux-headers-amd64 (in this order) were successfuly installed. Then according another I have also installed also bc. Most of packages i dont know purpose or further details. Nevermind.

I have also downladed original debian 4.4.218 (haven't tried yet) and from your recomendation downloaded GPL source WW6.10.9SRC for my current ReadyNAS OS 6. I have RN312 enterprise unit, and if i seen correctly, your Ultra2 has different GPL source files listing for download (just mentioning difference).

Bus 004 Device 002: ID 0bda:8157 Realtek Semiconductor Corp.

Make driver or attempt to install dkms driver, both still resulted with missing linux-header-4.4.218.x86_64.1 error message.

Then i tried to bash .. linux kernel headers compilation, (4th step of your guide), using in folder linux-4.4.218-x86_64, it took about one half or one hour. Few warnings or stacks bigger then expected byte size, but it finally went whole and completed, I cant judge warnings messages.

Then.. i tried install Realtek driver (8152), there were some faulty bytes or points, altought it did. No new adapter appeared, i dont know what symlink to where (no success). But i have done install of Realtek driver (8152) DKMS from github version and it finnaly completed finished, new adapter appeared. So i connected cable, and it works on 1gbit. Webadmin-network says 1gbit on all adapters even while no cable connected.

So is this the success or not? I have tried setting network adapter speed according driver readme.txt (uname -r says clearly 4.4.218.x86_64.1)

(ethtool -s eth2 autoneg on advertise 0x802f) should do 2,5gbit, seemed command done, but no change (in webadmin).

for 2,5gbit: ethtool -s eth0 autoneg on advertise 0x80000000002f says invalid command line parameter(s)

ethtool for 5gbit -s eth2 autoneg on advertise 0x180000000002f (says same, invalid command parameter(s))

readme says, it should work (0x802f does) for kernel below 4.10, and the other (long hexcodes) for newer kernel than 4.10 but those commands dont work

sudo ethtool -s eth2 speed 5000 duplex full autoneg on - says "cant advertise 5000 duplex full"

sudo ethtool -s eth2 speed 2500 duplex full autoneg on - seems command done, but no change

webadmin still showing 1gbit, should i rely on this? i have not yet 5gbit network hub/switch, so i can only connect  5gbit usb-rj usb stick to another, will this work and proove all work is done ok?