be careful with sshd config – how to fix PTY allocation request failed on channel 0 – PermitTTY yes yes yes

23.Oct.2018

as always… you should tweak your /etc/ssh/sshd_config for security

only allow password auth temporarily and only use public-key auth. it is easy to setup and no brute-force attack in this world can hack your server.

when you start to edit:

vim /etc/ssh/sshd_config
# tweak save quit
# and restart sshd
systemctl restart sshd

you SHOULD stay logged in, open a second terminal and test if your settings actually work.

DO NOT CLOSE THE CURRENT SESSION!

or you might NOT get back in and need a service-technician to attach a KVM-console (like the LanTronix Spider Duo) to your server or reset your root password X-D

change this to no:

PermitTTY yes

or you will get:

PTY allocation request failed on channel 0

and can not login.

nothing really usefull in the logs.

admin