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
- 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.
Table of Contents
About This Book
Introduction to Linux Systems
Cockpit - Web Portal for Administrator
Files and Directories
Users and Groups
Block Devices and Partitions
LVM (Logical Volume Manager)
SELinux - Security-Enhanced Linux
►Network Connection on CentOS
Internet Networking Tools
Software Package Manager on CentOS - DNF and YUM
vsftpd - Very Secure FTP Daemon
Postfix - Mail Transport Agent (MTA)
Dovecot - IMAP and POP3 Server
Email Client Tools - Mail User Agents (MUA)
LDAP (Lightweight Directory Access Protocol)
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