CentOS Stream 9 and 10: Complete Guide to Static IP Configuration and Package Repository Setup

Understanding CentOS Stream: The Rolling Release Future of Enterprise Linux

CentOS Stream occupies a unique position in the Red Hat ecosystem, serving as the upstream development branch for Red Hat Enterprise Linux (RHEL). Unlike traditional CentOS, which was a downstream rebuild of RHEL, CentOS Stream adopts a rolling release model that sits between Fedora and RHEL in the development pipeline.

This strategic positioning offers organizations and developers unprecedented visibility into upcoming RHEL features while maintaining enterprise-grade stability. Understanding the differences between CentOS Stream 9 and 10 is crucial for making informed deployment decisions.

Key Version Comparisons

CentOS Stream 9 aligns with the RHEL 9 series, featuring Kernel 5.14, Python 3.9 as the default, and GCC 11 for compilation. The system maintains traditional YUM/DNF package management and carries support through 2027 for full maintenance, extending to 2032 for critical security updates.

CentOS Stream 10, codenamed "Coughlan," represents a significant leap forward with Kernel 6.12 or higher, Python 3.12 delivering substantial performance improvements, and GCC 14 supporting modern language features. This version introduces innovative concepts like System Wide Image (SWI) and Bootable Container architectures, with expected maintenance extending into the early 2030s.

System Environment Verification

Before proceeding with configuration, verify your system environment. Typical deployments show:

CentOS Stream 10: Kernel version 6.12.0-212.el10.x86_64
CentOS Stream 9: Kernel version 5.14.0-687.el9.x86_64

These kernel versions confirm the underlying architecture differences between the two releases.

Configuring Static IP Addresses: The Modern NetworkManager Approach

The Shift from Legacy Network Scripts

CentOS Stream 9 and 10 have fundamentally changed network management. The traditional /etc/sysconfig/network-scripts/ifcfg-eth0 configuration files and the network service have been deprecated in favor of NetworkManager. This transition reflects broader industry trends toward dynamic, centralized network management.

NetworkManager stores connection profiles in /etc/NetworkManager/system-connections/, providing a unified interface for both GUI and command-line configuration.

Method One: Direct Configuration File Editing

Navigate to the NetworkManager connections directory:

cd /etc/NetworkManager/system-connections/
ls
# Output: ens160.nmconnection

Edit the connection profile to specify a static IP address (example: 192.168.0.132):

[connection]
id=ens160
uuid=89fcf374-9ca1-30b1-b1dd-ed124953574c
type=ethernet
autoconnect-priority=-999
interface-name=ens160
timestamp=1775042953

[ethernet]
duplex=half
speed=10000

[ipv4]
address1=192.168.0.132/24
dns=223.5.5.5;223.6.6.6;119.29.29.29;182.254.116.116;
gateway=192.168.0.2
method=manual

[ipv6]
addr-gen-mode=eui64
method=auto

[proxy]

Configuration Parameter Explanations:

address1: Specifies the static IP address and subnet mask in CIDR notation
dns: Lists DNS servers separated by semicolons. Using domestic DNS servers (for Chinese deployments) like 223.5.5.5 and 223.6.6.6 provides faster resolution
method: Set to "manual" for static configuration or "auto" for DHCP
gateway: Defines the default gateway for network traffic

After making changes, reload and restart NetworkManager:

systemctl restart NetworkManager
systemctl status NetworkManager

Verify the service status shows "active (running)" and check for any error messages in the logs.

DNS Configuration Propagation

Configuring DNS in the NetworkManager connection profile automatically updates /etc/resolv.conf:

cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 223.5.5.5
nameserver 223.6.6.6
nameserver 119.29.29.29
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 182.254.116.116

Note the warning about libc resolver limitations—only the first three nameservers may be reliably used by some applications.

Verification Steps

Confirm IP configuration success:

ip a
# Look for your interface with the configured IP address

ip r
# Verify routing table shows correct default gateway

ping qq.com
# Test external connectivity

Successful configuration shows the assigned IP address, correct routing, and working external connectivity.

Method Two: Using nmcli Command-Line Interface

The nmcli (NetworkManager Command Line Interface) tool provides a powerful alternative to direct file editing. Its advantages include:

Persistent Configuration: Changes survive reboots without additional steps
Real-Time State Reflection: Configuration immediately reflects in NetworkManager status
Validation: Built-in parameter validation prevents configuration errors

Common nmcli Operations:

Operation Type	Command Example	Description
Check Status	`nmcli general status`	View NetworkManager overall status
List Devices	`nmcli device status`	Show all network interfaces and connection states
Show Connections	`nmcli connection show`	List all saved connection profiles
Enable Connection	`nmcli connection up <ID>`	Activate specified connection profile
Disable Connection	`nmcli connection down <ID>`	Deactivate specified connection
Reload Configuration	`nmcli connection reload`	Reload configuration files after manual edits

Configuring Static IP via nmcli:

nmcli connection modify "ens33" \
    ipv4.addresses "192.168.0.132/24" \
    ipv4.gateway "192.168.0.2" \
    ipv4.dns "223.5.5.5,8.8.8.8" \
    ipv4.method manual

Activate the configuration:

nmcli connection down ens33 && nmcli connection up ens33

View detailed connection information:

nmcli connection show ens33

The nmcli approach offers better integration with automation scripts and reduces the risk of syntax errors in configuration files.

DNF and YUM Repository Configuration

Understanding DNF: The Next-Generation Package Manager

DNF (Dandified YUM) represents the evolution of package management for RPM-based Linux distributions. Designed specifically for Fedora, RHEL 8+, and CentOS Stream 9/10, DNF addresses the performance bottlenecks and functional limitations of its predecessor while maintaining familiar command syntax.

In CentOS Stream 9/10, the yum command exists as a symbolic link pointing to DNF:

ls -lh /usr/bin/yum
# lrwxrwxrwx. 1 root root 5 Feb 16 08:00 /usr/bin/yum -> dnf-3

ls -lh /usr/bin/dnf
# lrwxrwxrwx. 1 root root 5 Feb 16 08:00 /usr/bin/dnf -> dnf-3

This compatibility layer ensures existing scripts and documentation remain valid while users benefit from DNF's improvements.

Essential DNF Commands

Basic Installation:

sudo dnf install <package>                    # Install a single package
sudo dnf install <package1> <package2>        # Install multiple packages
sudo dnf install -y <package>                 # Auto-confirm installation (for scripts)

Package Management:

sudo dnf remove <package>                     # Uninstall a package
sudo dnf update                               # Update all installed packages
sudo dnf update <package>                     # Update a specific package
sudo dnf autoremove                           # Clean unused dependencies

Query and Search:

dnf search <keyword>                          # Search for packages
dnf info <package>                            # View package details
dnf provides /path/to/file                    # Find package providing a file
dnf list installed                            # List all installed packages

Repository Management:

dnf repolist                                  # List all enabled repositories
dnf repolist --verbose                        # Show detailed repository information
sudo dnf config-manager --enable <repo>       # Enable a repository
sudo dnf config-manager --disable <repo>      # Disable a repository

Cache Management:

sudo dnf clean all                            # Clear all cache (metadata and packages)
sudo dnf makecache                            # Rebuild cache after repository updates
sudo dnf clean packages                       # Remove downloaded .rpm files only

Transaction History:

dnf history                                   # View all operation records
dnf history info 5                            # View details of transaction #5
sudo dnf history undo 5                       # Undo transaction #5

Advanced Features:

dnf module list                               # List available modules
sudo dnf module enable php:8.0                # Enable specific module version
sudo dnf module install php                   # Install modular package
dnf download <package> --resolve              # Download package with dependencies
sudo dnf install ./*.rpm                      # Install locally downloaded RPMs
sudo dnf repair                               # Attempt automatic system repair

Configuring Repository Sources

Step 1: Backup Existing Repository Files

cd /etc/yum.repos.d/
ls
# Output: centos-addons.repo centos.repo

mkdir bak
mv *.repo bak/
ls
# Output: bak

Step 2: Configure Aliyun Mirror Repository

Create ali-centos.repo with the following content:

[baseos]
name=CentOS Stream $releasever - BaseOS
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/$basearch/os/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1

[baseos-debug]
name=CentOS Stream $releasever - BaseOS - Debug
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/$basearch/debug/tree/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0

[baseos-source]
name=CentOS Stream $releasever - BaseOS - Source
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/BaseOS/source/tree/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0

[appstream]
name=CentOS Stream $releasever - AppStream
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/os/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1

[appstream-debug]
name=CentOS Stream $releasever - AppStream - Debug
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/debug/tree/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0

[appstream-source]
name=CentOS Stream $releasever - AppStream - Source
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/AppStream/$basearch/debug/tree/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
enabled=0

[crb]
name=CentOS Stream $releasever - CRB
baseurl=https://mirrors.aliyun.com/centos-stream/$stream/CRB/$basearch/os/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
gpgcheck=1
repo_gpgcheck=0
metadata_expire=6h
countme=1
enabled=1

Step 3: Configure Additional Repositories

Create ali-addons.repo for additional repository components including HighAvailability, NFV, RT, ResilientStorage, and extras-common repositories. Each follows the same pattern with appropriate baseurl configurations.

Step 4: Install EPEL Repository

The Extra Packages for Enterprise Linux (EPEL) repository provides additional software packages:

dnf install epel-release

Verify installation:

pwd
# /etc/yum.repos.d

ls
# ali-addons.repo ali-centos.repo bak epel.repo epel-testing.repo

Step 5: Refresh Cache and Update

dnf clean all      # Clear all cached data
dnf makecache      # Rebuild package cache
dnf update         # Update all installed packages

Best Practices and Considerations

Network Configuration Best Practices

Always backup configurations before making changes
Test connectivity after each configuration change
Use domestic DNS servers for better resolution speed in regional deployments
Document all changes for future reference and troubleshooting
Consider IPv6 requirements for future-proofing network configurations

Repository Configuration Best Practices

Use trusted mirrors like Aliyun, Tencent, or official CentOS mirrors
Enable only necessary repositories to reduce attack surface
Regularly update package cache to ensure security patches are applied
Monitor repository health and switch mirrors if issues arise
Consider bandwidth when selecting mirror locations

Troubleshooting Common Issues

Network Connectivity Problems

If network configuration fails:

Check NetworkManager service status: systemctl status NetworkManager
Verify connection profile syntax in /etc/NetworkManager/system-connections/
Check for conflicting network services
Review system logs: journalctl -u NetworkManager

Repository Access Issues

If package installation fails:

Verify network connectivity to mirror servers
Check repository configuration syntax
Clear and rebuild cache: dnf clean all && dnf makecache
Try alternative mirror servers if problems persist

Conclusion

CentOS Stream 9 and 10 represent the future of enterprise Linux, offering rolling updates with enterprise stability. Mastering NetworkManager for network configuration and DNF for package management is essential for successful deployments.

The transition from legacy network scripts to NetworkManager and from YUM to DNF reflects broader industry trends toward more sophisticated, integrated system management. Understanding these tools not only ensures successful configuration but also prepares administrators for the evolving landscape of enterprise Linux administration.

Whether deploying CentOS Stream 9 for long-term stability or CentOS Stream 10 for cutting-edge features, the configuration principles remain consistent: understand the tools, follow best practices, and always verify changes before considering the configuration complete.