Question: I used to have a Server 2003 R2 Hyper-V VM instance running on an Server 2012 R2. The performance was very good. THen, I was told that 2003 wasn't being supported anymore by a software package I use, so I upgraded to 2008 R2, and that's when all my SMB shares took a nosedive.

When I attempt to navigate to my network drive using SMB2 (verified using wireshark), When I open a folder, it takes almost a minute to list the content of the folder. Using 2003, it was instantaneous. Then, when I move my mouse cursor over a file in the folder, windows explorer locks up for another minute. Wireshark doesn't produce anything other than Keep-Alive messages while I wait for a response from the server. Any ideas as to why this is happening after my upgrade?

Answer: 
I should have read [the manual](https://www.freedesktop.org/software/systemd/man/systemd.link.html) more carefully.

> 
> The first (in lexical order) of the link files that matches a given device is applied. Note that a default file 99-default.link is shipped by the system. Any user-supplied .link should hence have a lexically earlier name to be considered at all.
> 
> 
> 

Renaming `/etc/systemd/network/ens19.link` to `/etc/systemd/network/00-ens19.link` helped.

`[MATCH]` should be `[Match]` and `[LINK]` should be `[Link]`.

To apply a changed .link file to the link I can reboot or run 

```
udevadm test-builtin net_setup_link /sys/class/net/ens19

```

(Because .link files are processed by udev and not systemd-networkd, restarting systemd-networkd is insufficient.)
As per [systemd.network](https://www.freedesktop.org/software/systemd/man/systemd.network.html) link aliases are not (yet?) supported.