https://drive.google.com/file/d/14rmLiroT5eZK_2R6J8fNbXlAUQXT7pou/view?usp=sharing

1. Understanding IP Assignment Methods

Key Concepts

• DHCP: Automatic IP assignment (default for new connections)
• Static: Manual IP configuration (required for servers)
• Multiple IPs: Assign multiple addresses to one interface (virtual IPs)
• IPv6: Next-generation addressing (128-bit vs IPv4's 32-bit)

💡 Critical Note:

RHEL 9 uses NetworkManager—all changes should be made via nmcli or nmtui.

2. Creating Static IPv4 Connections

Basic Static IP Setup

# Create static connection
nmcli con add type ethernet con-name ens224 ifname ens224 \\\\
  ipv4.addresses 192.168.0.145/24 \\\\
  ipv4.gateway 192.168.0.1 \\\\
  ipv4.dns 8.8.8.8 \\\\
  ipv4.method manual

# Activate connection
nmcli con up ens224

# Verify
ip a show ens224

⚠️ Fix from Your Notes:

• Correct parameter: ipv4.addresses (not ipv4.Address)
• Correct parameter: ipv4.gateway (not gw4)
• Must specify ipv4.method manual for static IPs

3. Adding Multiple IP Addresses

Assign Secondary IP

# Add second IP to existing connection
nmcli con modify ens256 +ipv4.addresses 192.168.0.155/24

# Add additional DNS
nmcli con modify ens256 +ipv4.dns 8.8.4.4

# Reload and activate
sudo nmcli con reload
nmcli con up ens256

# Verify
ip a show ens256

Remove Secondary IP

# Remove specific IP
nmcli con modify ens256 -ipv4.addresses 192.168.0.155/24

# Remove DNS entry
nmcli con modify ens256 -ipv4.dns 8.8.4.4

# Reload and activate
sudo nmcli con reload
nmcli con up ens256