SSH¶
SSH Without PasswordAuthentication¶
Gen key
ssh-keygen -t rsa
Copy to remote
# ssh-copy-id -i ~/.ssh/id_rsa.pub user@remote-system
# or
# may be on .ssh forder not exist on remote
# cat ~/.ssh/*.pub | ssh user@remote-system 'umask 077; cat >>.ssh/authorized_keys'
source: https://www.schlittermann.de/doc/ssh.html
Issues¶
Connection to nagios.vavmaster.de closed by remote host. Connection to nagios.vavmaster.de closed. behind fritzbox
Fix
cat /proc/sys/net/ipv4/tcp_keepalive_time echo "60" > /proc/sys/net/ipv4/tcp_keepalive_timepersistent
echo "net.ipv4.tcp_keepalive_time = 60" >> /etc/sysctl.conf
SSH TUNEL¶
New project is active. See code/tunel project
ssh -fN -RREMOTEDOMAIN:10004:localhost:22 USER@REMOTEDOMAIN
or use autossh (reconnects automaticaly)
autossh -M 10901 -fN -o "PubkeyAuthentication=yes" -o "StrictHostKeyChecking=false" -o "PasswordAuthentication=no" -o "ServerAliveInterval 60" -o "ServerAliveCountMax 3" -R REMOTEDOMAIN:10009:localhost:22 root@REMOTEDOMAIN
Try to connect
ssh REMOTEDOMAIN -p 10009
Check also sshd conf entry
GatewayPorts clientspecified
Check
netstat -nap
Example
ssh -fN -R a.moqops.com:8080:localhost:8080 relay@moqops.com
Important
DNS must match the for domain. Check for example with ifconfig. It must not be a public ip, IP must be the same as on Interface.
To make tunel on startup DO systemd¶
Create a stat script
# cd /usr/local/bin
# cat > tunel
#!/bin/bash
autossh -M 10999 -fN -o "PubkeyAuthentication=yes" -o "StrictHostKeyChecking=false" -o "PasswordAuthentication=no" -o "ServerAliveInterval 60" -o "ServerAliveCountMax 3" -R 192.168.8.102:22:localhost:22 root@nagios.vavmaster.de
# chmod a+x tunel
# cd /etc/systemd/system
# cat > tunel.service
[Unit]
Description=tunel Unit
Wants=network-online.target
After=network.target network-online.target
[Service]
User=root
Type=simple
ExecStart=/usr/local/bin/tunels/kafka
RestartSec=5
Restart=always
[Install]
WantedBy=multi-user.target
# systemctl enable tunel.service
# reboot
# NOW
# systemctl enable tunel.ssh.service
# systemctl start tunel.ssh.service
Connection from outside than $ ssh monitoring.vavmaster.de -p 2222 -l vavvav
To debug connection¶
ssh -vvv REMOTEDOMAIN -p 2222 -l USER
SSH Agent¶
If agent are active use for axample this rsync command to provide the keygen
rsync -avzhe ssh -A REMOTEHOST:/mnt/temp/* .
See scripts * scripts.
