Add the following option in /etc/ssh/sshd_config
AuthenticationMethods publickey,password
Category: Knowledgebase
SEOS (ssh server Access Control) – Method for ssh authentication fails for ssh server
If SEOS authentication method fails than it is not supported by your Linux flavor and should be disabled in /etc/ssh/sshd_config.
Unable to add host to cluster of hypervisors in Linux virtualization
First of all delete host from user interface than add correct selinux context to the log file.
chcon -t httpd_log_t /var/log/ovirt-engine/logfile.log
restorecon /var/log/ovirt-engine/logfile.log
Reattach host via user interface.
Restrict ftp user login to ftp server denying access to operating system
When you create new users for ftp server access, do not assign shell to those users.
# useradd -s /sbin/nologin webconn
For existing user, use “usermod -s” to change the user’s shell to /sbin/nologin.
# usermod -s /sbin/nologin webconn
How to add a binary attribute in Linux?
At the command-line, the following syntax is used;
attribute:< file:///FILE_FULL_PATH
Note: There should be no space character between the colon ‘:’ and the less-than sign ‘<‘.
As an example; jpegPhoto:< file:///home/webconn/picture.png
Server hangs for a long time on firewalld service shutting down or on reboot
Add/edit following option in /etc/firewalld/firewalld.conf;
CleanupOnExit=no
Using option CleanupOnExit=yes in /etc/firewalld/firewalld.conf flush firewall rules and try to off-load nf_conntrack module. If server hangs, it is because something is stopping nf_conntrack module from unloading quickly.
Try running systemctl stop firewalld and see if service hangs. If firewalld service start is success you are likely not having this issue.
System panic error – IPv4: Attempt to release alive inet socket | IPv4: Attempt to release TCP socket in state 1 [kernel address]
The main reason for this system panic error is that socket is being closed while packet sent via that socket is queued to userspace. After userspace reinjects (userspace or another netfilter rule asks for the packet to get queued again,) the refcount transition will be 1 -> 0 -> 1 (-> 0), thus double-free occurs.
This error is being managed in bugzilla 1885682 and 1886557.
How to configure a SSH tunnel?
On the client machine perform the following step:
[root@host]# ssh -N -L :: user@remote-machine-ip
From a new console/terminal execute the telnet command as follows:
[root@host]# telnet localhost
This kb is relevant to the following;
- Encrypt the traffic by SSH tunneling the connection to remote host.
- Encrypt unencrypted network traffic