Configure DHCP (Dynamic Host Configuration Protocol) Server in RHEL/Centos 7

### Install DHCP Server [root@testos ~]# yum -y install dhcp ### Configure DHCP Server [root@testos ~]# vi /etc/dhcp/dhcpd.conf # create new # specify domain name option domain-name “unixtest.com”; # specify name server’s hostname or IP address option domain-name-servers testos.unixtest.com; # default lease time default-lease-time 600; # max lease time max-lease-time 7200; # this DHCP server … Read more

Setup and Configure Network Aggregation Under Solaris 10 / Solaris 11

An aggregation is similar to an IPMP link created for failover, but has other advantages: Early versions of Solaris 10 do not have this facility – you would need to download the Sun Trunking software to get it. ### Solaris 10 configuration: To show the available network interfaces: [root @ soltest]~ # dladm show-link LINK … Read more

Configure Static IP Address on Solaris11

//Check current ip configuration status # dladm show-phys # ipadm show-if # ipadm show-addr //Check the interfaces name # dladm show-phys — output Example —LINK MEDIA STATE SPEED DUPLEX DEVICEnet0 Ethernet up 1000 full e1000g0 –> Attentiom to this linenet1 Ethernet unknown 0 unknown pcn0 =============================================================================================== # ipadm create-ip net0 //Check status # ipadm show-if … Read more

Is it safe to set net.ifnames=0 in RHEL7, RHEL8 and RHEL9?

Issue: Is it safe to disable Consistent Device Naming by setting net.ifnames=0 on the kernel command line in RHEL7, RHEL8 and RHEL9? Why can I no longer use the 70-persistent-net.rules file to force persistent ethX names like I could in earlier versions of Red Hat Enterprise Linux? Resolution: No. Red Hat strongly recommend that the … Read more

How to Move IP Configuration From One Network Device to Another Device in Solaris

Use the following procedure if you need to preserve the IP configuration that is associated with one network device and then move that configuration to another network device. You might perform this procedure as a prelude to removing a network card from the system or when changing a network cable connection. For example purposes only, … Read more

Nmap Cheat Sheet : All the Commands & Switches

Nmap is Linux command-line tool for network exploration and security auditing. This tool is generally used by hackers and cybersecurity enthusiasts and even by network and system administrators. It is used for the following purposes: Real time information of a network. This Nmap cheat sheet help you master what is arguably the most useful tool in … Read more

Enable SSL/TLS for vsftpd to use Secure FTP(SFTP) connections in RHEL/Centos

### Create self-signed certificate. [root@testos ~]# cd /etc/pki/tls/certs[root@testos certs]# openssl req -x509 -nodes -newkey rsa:2048 -keyout vsftpd.pem -out vsftpd.pem -days 365Generating a 2048 bit RSA private key……++++++…….++++++ writing new private key to ‘/etc/pki/tls/certs/vsftpd.pem’ You are about to be asked to enter information that will be incorporatedinto your certificate request.What you are about to enter is … Read more

Install and configure vsftpd to configure FTP Server in RHEL/Centos

### Configure Vsftpd [root@testos ~]# yum -y install vsftpd ### Edit/Update vsftpd Configuration file [root@testos ~]# vi /etc/vsftpd/vsftpd.conf # line 12: no anonymous anonymous_enable=NO # line 82,83: uncomment ( allow ascii mode ) ascii_upload_enable=YES ascii_download_enable=YES # line 100, 101: uncomment ( enable chroot ) chroot_local_user=YES chroot_list_enable=YES # line 103: uncomment ( specify chroot list ) … Read more

Install and Configure Cacti Network Graphing Tool on RedHat / CentOS

Cacti is a network graphing tool similar to MRTG. How do I install and configure common options to collect SNMP data and various other data (such as system load, network link status, hard disk space, logged in users etc) into an RRD? From the official project site: Cacti is a complete frontend to RRDTool, it … Read more