ifconfig has been deprecated in favour of the ip utility for many years and was removed in RHEL/CentOS 7. Being a creature of habit, I choose to install it anyway so when I reach for it I don't waste time realizing and correcting my mistake. It is available in the net-misc package:
dnf install net-misc
As of CentOS Stream 9 the package is now named net-tools:
dnf install net-tools
screen was included in the default repositories distributed with RHEL/CentOS 7 and earlier. Since RHEL/CentOS 8 it is now necessary to configure the Extra Packages for Enterprise Linux (EPEL) repos, which you're probably going to need eventually anyway.
dnf install epel-release
Now you can install screen as usual:
dnf install screen
Install the NFS utilities, start and configure the service to run automatically on boot:
RHEL/CentOS
dnf install nfs-utils nfs4-acl-tools
systemctl enable nfs-server.service
systemctl start nfs-server.service
To configure firewalld to permit network access to the NFS services run:
firewall-cmd --permanent --add-service=nfs
firewall-cmd --permanent --add-service=rpc-bind
firewall-cmd --permanent --add-service=mountd
firewall-cmd --reload
Debian/Ubuntu
apt install nfs-kernel-server rpcbind
systemctl enable nfs-kernel-server
systemctl start nfs-kernel-server
To configure ufw to permit network access to the NFS services run:
ufw allow from 192.168.0.0/24 to any port nfs
ufw enable
Configuration files are located at /etc/nfs.conf and /etc/nfsmount.conf.
Create or edit /etc/exports:
/mnt/share1 192.168.0.0/24(ro)
/mnt/share2 192.168.0.0/24(rw,async)
/mnt/share3 192.168.0.0/24(rw,sync)
/mnt/share4 192.168.0.0/24(rw,sync,no_all_squash,root_squash)
Specify the single IP address or range in CIDR notation that a share should be accessible to followed by its options in (brackets).
See man exports for detailed information about per-share configuration options.
To reload the exports configuration live, run:
exportfs -ar
To configure disk quotas please see Mass Virtual Hosting Part Three: Disk Quotas (including NFS).
RHEL/CentOS
dnf install nfs-utils nfs4-acl-tools
Debian/Ubuntu
apt install nfs-common
To view the exported shares on the remote server:
showmount -e 192.168.0.100
To mount a remote share:
mount -t nfs 192.168.0.100:/mnt/share1 /mnt/shared
To add a remote share to fstab (automatically mount at boot, simplified mount /mountpoint):
192.168.0.100:/mnt/share1 /mnt/shared nfs defaults 0 0
![[attachment-qFVVzQ]](/files/2024/03/06/nmtui.png)
Having discovered nmtui only some time after familiarizing myself with nmcli - under the incorrect assumption that it would be necessary - I am adding this some time since publishing the body of the following article so that you might not make the same error:
I realize that for 99% of readers I am about to kill an article, but better for you to get the goods off the bat than to waste anyone's time. Before we dig into nmcli it would be remiss for me to not inform you of its menu-based ncurses relative that is so much easier that it does not even warrant its own article: nmtui. It is quick and feature-full enough to render knowing nmcli syntax relevant more-or-less exclusively to those looking to implement interfacing with Network Manager within shell scripts.
For those of you remaining so-inclined, I present the following...
I have always favoured directly editing network configuration plaintext files (e.g: /etc/sysconfig/network-scripts/ifcfg-ifname on RedHat flavours). However it has for some time been more ideologically correct to manage the network configuration on many distributions via the NetworkManager daemon. More importantly, it is intrusive, obnoxious and annoying to disable NM such that it does not interfere with manual configurations (lookin' at you, Ubuntu). So this is my attempt to find religion.
Unless there is a crazy good reason, I don't do GUIs on servers. nmcli is provided to interface with NetworkManager from the command line. It can be used in CLI (direct) or shell (interactive) mode, as root/via sudo:
To effect the changes you must raise or reload the interface, using nmcli:
or on RedHat flavours simply:
Note the following:
The IPv4.method property can be set to any one of:
IPv6 is configured in the same way; see https://developer.gnome.org/NetworkManager/stable/settings-ipv6.html for IPv6 configuration options and modify your syntax accordingly.
As root/via
Again the connection must either be reloaded or raised to take effect:
When troubleshooting network services it is essential to be able to see that a service is not just running but also accessible. Not every tool we cover will be available in any given environment; lsof in particular is rarely a part of default installations. It may not be possible to quickly or easily install your favourite utility, particularly on an outdated system. Therefore it is helpful to carry many tools in your belt. A listening service is not necessarily open; we will also cover using a port scanner like nmap to verify accessibility from remote hosts and how to check your netfilter rules with iptables.
lsof -i -n -P
lsof -i -n -P | grep ":80"
netstat -plnt
ss -tunlp
nmap 192.168.0.100 -p 1-65535