Week 04: DHCP - Skirmigle/SYS-255-Tech-Journal GitHub Wiki

Summary:

Week 4 largely consisted of setting up DHCP across the network of VMs. Linux system administration was also explored in more depth as system and file permissions as well as the management of configuration files were both explored.

Assignments:

Lab 4:

Lab 4 revolved around creating, configuring, and implementing DHCP on the network of VMs. Implementing DHCP involved changing configuration files, restarting and enabling system programs, and reconfiguring windows properties.

Linux file permissions:

Linux file permissions are determined by a file or directories user owner and group owner. A file or directory will have a set level of permissions for the user owner, group owners, and other users which determines an individuals level of access to the given file/directory. In this assignment we create users and groups to test assigning permissions to both.

Securing SSH:

The securing SSH lab revolved around being able to reconfigure the DHCP01 VM to not allow SSH access to the ROOT account. to do this you must edit the sshd_conf file to change the ssh configuration settings, specifically the PermitRootLogin value must be set to no.

Research References:

  • Man dhcpd.conf: this command takes you to the dhcpd.conf files manual, it was here that I found out how to set lease lengths.

Important concepts and tools:

  • SSH: This is a command that allows remote access to a device from another device on the DNS.

  • Linux File Permissions: Linux file permissions determine who can access a file on Linux system. Any given file will have a given user and group owner, the user owner, members of the group owner and other users each have set read, write, and execute permissions.

  • Securing SSH: to disable root login, I edited the sshd_conf file to change the ssh configuration settings, specifically the PermitRootLogin value was set to no. the difference between /var/log/btmp and journalctl -u sshd is that /var/log/btmp is a legacy binary file that records only failed login attempts from several services, while journalctl -u sshd records all log messages from the sshd service.

Important URLs:

ProxMox: https://prox01.cyber.local

ViewPortal: https://viewportal.champlain.edu/portal/webclient/#/desktop