Network Connection on CentOS

Linux Tutorials - Herong's Tutorial Examples

∟Network Connection on CentOS

This chapter provides introductions and tutorial on network configuration and firewall on CentOS systems. Topics include introduction of Ethernet connection with auto DHCP configuration; 'ifconfig' to view current network configuration; 'firewalld' daemon and 'firewall-cmd' CLI as firewall frontend tools; 'nftables' daemon and 'nft' CLI as firewall backend tools; 'nmap' as network scanner; 'netstat' as network activity monitor.

Setup Ethernet Connection on CentOS

Network Firewall Tools on CentOS

"firewalld" and "firewall-cmd" on CentOS

Manage Multiple Firewall Zones

"nftables" and "nft" on CentOS

"iptables" Command on CentOS

"nmap" - Network Mapper on CentOS

Monitor Network Services on CentOS

"ifconfig" - Trace Routes to Remote Host

"traceroute" - Trace Routes to Remote Host

"route" - Upate Routing Table

"netstat" - Display Network Statistics

"lsof" - List of Open Files

Takeaways:

Ethernet connection setting can be automatically done with DHCP (Dynamic Host Configuration Protocol) service from the local network on CentOS systems.
"ifconfig" command can be used to view the current network configuration on all network interfaces on CentOS systems.
"firewalld" daemon and "firewall-cmd" CLI (Command Line Interface) are the frontend tools to manage network firewall on CentOS systems.
Multiple firewall zones are supported to set up different levels of security permissions for different source IP addresses/ranges.
"nftables" daemon and "nft" CLI (Command Line Interface) are the backend tools to manage network firewall on CentOS systems.
"iptables" command is replaced by "nftables" daemon and "nft" CLI on CentOS 8 systems.
"nmap (Network Mapper)” is a network exploration tool and security scanner.
"netstat (Network Status)” is a network activity monitor tool.
"ifconfig" allows you to manage network interface configurations.
"traceroute" allows you to trace routes (or gateways) between the local host and a given remote host.
"route" allows you to update the network routing table currently used in the system.
"lsof -i" allows you to see network connections as open files.