RHEL9

New Deployment

A collection of common things to do on almost any new RHEL deployment.

Software To Install

subscription-manager repos --enable codeready-builder-for-rhel-9-$(arch)-rpms

dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm

dnf install vim wget tmux htop iftop net-tools bind-utils traceroute tcpdump nmap mtr net-snmp-utils rsync git lsof usbutils yum-utils unzip python3 open-vm-tools nfs-utils -y

dnf group install "Development Tools"

Networking

Bonding

A network bond is a method to combine or aggregate physical and virtual network interfaces to provide a logical interface with higher throughput or redundancy. In a bond, the kernel handles all operations exclusively. You can create bonds on different types of devices, such as Ethernet devices or VLANs.

Example

In this example, I was able to successfully bond two links to a Juniper EX3300 using LACP (802.3ad):

Note Info:  Be sure to delete any existing connection profiles that are applied to any interfaces you plan to use as slaves.

nmcli connection add type bond con-name bond0 ifname bond0 bond.options "mode=802.3ad,lacp_rate=fast"

nmcli connection modify bond0 connection.autoconnect-slaves 1

nmcli connection add type ethernet slave-type bond con-name bond0-port0 ifname enp129s0f0 master bond0

nmcli connection add type ethernet slave-type bond con-name bond0-port1 ifname enp129s0f1 master bond0

nmcli connection modify bond0 ipv4.addresses '10.144.30.20/24' ipv4.gateway '10.144.30.1' ipv4.dns '10.144.30.4,10.150.30.2' ipv4.dns-search 'lambnet.us' ipv4.method manual

Verification

cat /proc/net/bonding/bond0

Also, unplug one member cable of the bond at a time while performing a ping, to confirm link stays up.

Sources

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/configuring_and_managing_networking/configuring-network-bonding_configuring-and-managing-networking

https://www.kernel.org/doc/Documentation/networking/bonding.txt

Disk/Filesystem

Erase a Disk

dd if=/dev/zero of=/dev/sdx status=progress && sync

Users & Passwords

Show Password Expiration, etc.

chage -l bob

passwd --status bob

Remove Password Expiration

chage -E -1 bob

Expire A Password Immediately

chage -E 0 bob

Remove Password Validation Checking

chage -m 0 -M -1 bob

Disable a User's Shell (prevents login)

usrmod -s /sbin/nologin bob

List Sudo Privileges

sudo -l