Category Archives: Security

To configure the timeout for SSH sessions, let’s see where the SSH server configuration file is located:

sudo find / -name sshd_config

Open it in any text editor, for example nano:

sudo nano /etc/ssh/sshd_config

Continue reading “Configuring SSH session timeout”

Let’s say that several users are connected through SSH.

First look at the list of online users:

w

Suppose the following information is displayed (where test is the user’s login):

USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
test     tty1                      11:20    1:07   0.03s  0.03s -bash
test     pts/0    192.168.1.5      11:21   13.00s  0.02s  0.02s -bash
test     pts/1    192.168.1.3      11:21    0.00s  0.02s  0.00s w

tty1 – it is a client logged in locally, that is, it is located near the computer.
pts/1 – judging for example on IP and WHAT, let’s assume that it’s us, accordingly pts/0 is the client of which we want to disconnect.

See the list of processes and their PID:

ps faux |grep sshd

At me it was displayed:

root       946  0.0  0.5  65508  5368 ?        Ss   12:00   0:00 /usr/sbin/sshd -D
root      1147  0.0  0.6  92828  6920 ?        Ss   12:01   0:00  \_ sshd: test [priv]
test      1178  0.0  0.3  92828  3384 ?        S    12:01   0:00  |   \_ sshd: test@pts/0
root      1192  0.0  0.6  92828  6592 ?        Ss   12:02   0:00  \_ sshd: test [priv]
test      1223  0.0  0.3  92828  3532 ?        S    12:02   0:00      \_ sshd: test@pts/1
test      1248  0.0  0.0  15468   956 pts/1    S+   12:25   0:00              \_ grep --color=auto sshd

We find test@pts/0 and accordingly 1178 is the required PID.

We terminate the process by specifying its ID, after which the user will immediately disconnect:

sudo kill -9 1178

See also my articles:
Configuring SSH session timeout
Installing and Configuring SSH