@Kingsley,
You stated
I did that because let's encrypt extention won't install
and note the following.
The issue with the letsencrypt extension is a separate issue, that you should be taken care of separately.
In general, any installation issue should not be resolved by adding lines to the /etc/hosts file, I will (briefly) explain later.
In fact, the
tcp_window_scaling settings are
often the root cause of the problem: just use the command
echo 0 > /proc/sys/net/ipv4/tcp_window_scaling
If and
only if that does not work (read: not even after a reboot, a reboot is recommended), you can try to use other work-arounds.
Why should you prefer to not change the /etc/hosts file?
Well, changing the /etc/hosts file implies that you, even before DNS can be referenced, assign hostnames to IPs.
For instance, adding "68.232.34.73 autoinstall.plesk.com" to /etc/hosts implies that you assign the hostname autoinstall.plesk.com to IP 68.232.34.73,
before DNS can be referenced.
The problem in this is really that you assign static values (IPs and hostnames), while they can change in real life (for instance, DNS changes, IP changes, hostname changes etc.)
So, if the IP address of hostname autoinstall.plesk.com changes to 93.184.221.133, a line "68.232.34.73 autoinstall.plesk.com" in /etc/hosts will NOT help and issues reoccur.
Now, have a look at the KB article cited by
@UFHH01 and you can see that at least three IPs and 4 hostnames are used.
In short, using a work-around involving /etc/hosts is not good, since it really will sooner or later result in the problems reoccurring.
Moreover, the analysis of the root cause of the problem has been done by me and I have suggested the tcp_window_scaling solution: you can really take from me that the other solutions from the KB article are not working, if the tcp_window_scaling settings are improper.
Hope the above helps.
Regards..........