19.3. Using Toolbx for troubleshooting a host system

Procedure

1. Install the systemd suite to be able to run the journalctl command:

   ⬢[root@toolbox ~]# dnf install systemd

2. Display log messages for all processes running on the host:

   ⬢[root@toolbox ~]# j journalctl --boot -0
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: microcode: updated ear>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: Linux version 6.6.8-10>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: Command line: BOOT_IMA>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: x86/split lock detecti>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: BIOS-provided physical>

3. Display log messages for the kernel:

   ⬢[root@toolbox ~]# journalctl --boot -0 --dmesg
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: microcode: updated ear>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: Linux version 6.6.8-10>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: Command line: BOOT_IMA>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: x86/split lock detecti>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: BIOS-provided physical>
   Jan 02 09:06:48 user-thinkpadp1gen4i.brq.csb kernel: BIOS-e820: [mem 0x0000>

4. Install the nmap network scanning tool:

   ⬢[root@toolbox ~]# dnf install nmap

5. Scan IP addresses and ports in a network:

   ⬢[root@toolbox ~]# nmap -sS scanme.nmap.org
   Starting Nmap 7.93 ( https://nmap.org ) at 2024-01-02 10:39 CET
   Stats: 0:01:01 elapsed; 0 hosts completed (0 up), 256 undergoing Ping Scan
   Ping Scan Timing: About 29.79% done; ETC: 10:43 (0:02:24 remaining)
   Nmap done: 256 IP addresses (0 hosts up) scanned in 206.45 seconds

   • The -sS option performs a TCP SYN scan. Most of Nmap’s scan types are only available to privileged users, because they send and receive raw packets, which requires root access on UNIX systems.